Sharpen is a very special enchantment, gained by certain items that kill a Spikagi.

Wait, certain items? What items? Sharpen only affects solid items, and then only organic objects (like bone, wood, or enamel), or objects made of or containing organic carbon (coal, bone steel). However, Sharpen most strongly affects paper and diamonds.

Enough already, what does it do? The Sharpen enchantment causes any straight lines, edges, or points on an object (let's say a wood, coal, or bone object) to become as sharp as a steel razor. Those same areas on a steel item will be twice as sharp, but if those areas were already sharp, they will be four times as sharp. A Sharpened steel battleax or sword will therefore be four times as sharp as a steel razor.

Paper, however, becomes ridiculously sharp under the effect of Sharpen, becoming four times as sharp as an obsidian scalpel. In my estimation, a Sharpened origami katana should be able to cut through a cement slab, even a modern car, like it's melted butter. Diamonds, however? Once Sharpened, a cut diamond will become like a plasma sword or lightsaber, cutting through objects with the same ease and precision.

This sharpness does not go away; Sharpened items stay sharp, you can't blunt, dull, chip or file down (erode away) their points or edges. If an object is too soft or brittle to hold and keep an edge (or sharp point), Sharpen nullifies that, giving it the same strength (hardness, tensile strength) and flexibility as tempered steel, while retaining the benefits of the Sharpen enchantment (so there's no blunting, dulling, chipping or filing a Sharpened object). (So the aforementioned katana will have all of that but with the addition of ridiculous sharpness, while the diamond will retain its incredible hardness but gain the tensile strength and flexibility of tempered steel, making it much less likely to shatter).

So, my question is, What Benefits Would The Sharpen Enchantment Have On Items?


  1. The best answer should start with a shortlist (summary) of what items or kinds of items would be benefited by this Enchantment and why. Remember, items can only be added if they can be used to kill a Spikagi. (Paper should be able to do that, right? I mean, stab a Spikagi's eye with a paper blade, choke it with a crumpled piece of paper....)

  2. The best answer should have categories or groups of items that would be benefited by this Enchantment, for #3 below.

  3. Each category of item that would be Benefited by this Enchantment should be thoroughly analyzed to determine how much this Enchantment would benefit them overall.

  4. The best answer should, preferably, also account for whether the Sharpen enchantment really benefits paper, or rather, paper armor, and diamonds. I wanted to make paper and diamond viable for military use through this Enchantment, so those who find out about this Enchantment's effect upon paper and diamonds can use them to their advantage.

Please Note:

Firstly, my understanding of blades is limited, but I do appreciate knowing that a blade can only cut so far depending on how thick it is.

As for evaluating how much sharper an item becomes due to Sharpening, I suppose a crude scale, akin to Moh's Scale of hardness for minerals, could be constructed, determining an object's sharpness by the hardest materials it can cut.

As for balancing durability and sharpness, I believe that is pretty well covered by the Enchantment itself. Steel is pretty durable, and Sharpened objects don't blunt or file down....

  • $\begingroup$ I like this a lot better than the rubberizing enchantment. :-) $\endgroup$
    – JBH
    Commented Apr 18, 2021 at 3:34
  • $\begingroup$ Sharp is not enough, thickness also matters, cutting a cement pillar for instance requires you to lift whatever the pillar is holding up the thickness of the blade. then you get drag on the sides of the blade. Also if you want a sword maximized for cutting you want something thinner with a stronger curve than a katana. $\endgroup$
    – John
    Commented Apr 18, 2021 at 4:12
  • 1
    $\begingroup$ how do you evaluate the "n times sharper"? Razors manufacturers, who do not go easy with marketing, just keep adding more blades... $\endgroup$
    – L.Dutch
    Commented Apr 18, 2021 at 6:46
  • $\begingroup$ @L.Dutch-ReinstateMonica♦ that's why it's perfect. n times sharper just means we know how many blades they have. The new razor 200 is 200 times as sharp, as it's got 200 blades for extra smoothness! $\endgroup$
    – Trioxidane
    Commented Apr 18, 2021 at 8:26
  • $\begingroup$ A simple functional way of measuring sharpness is the force required to cut the same substance. knifesteelnerds.com/2018/08/06/sharpness-vs-cutting-ability although even then you have different parts of the cut to measure. $\endgroup$
    – John
    Commented Apr 19, 2021 at 15:05

3 Answers 3


The is a bit to unpack here.

First Katana are not great swords if you have better materials to work with, Katana were heavy with little curve because that was the best the material could do. (basically a two handed short blade sabre). To make a sword cut better you want a stronger curve, which increases the amount of blade edge that passes through the cut. You want a lighter blade as well, Katana are a heavy bladed sword for their length, again due to the limitations of the material they had to work with.

this is the kind of curve you want to maximize cutting power.

enter image description here

What is the best material to use this enchantment on, somethin already sharp that will have better wear resistance or strength when you make it as strong and flexible as steel. you need somtyhing that wears better than steel, we can make steel swords sharper but there is no point as they will dull or roll. Diamond cannot be made very sharp without precision machines, it does not naturally fracture into a sharp edge, so if you are using medieval tech not a great choice. The best thing you can use this enchantment on is obsidian.

Obsidian produces one of the sharpest blades we can currently make, obsidian is used for eye surgery, but it is too brittle to make large blades from. The brittleness also makes it wear quickly as bits break off when cutting resistant material. Done correctly it has a mono-atomic edge, literally as sharp as it is possible to make matter. The sharpest real world obsidian scalpel blades will cut the end of your finger just using its own weight. You magically enhanced obsidian blades will will go through a body like it is barely there. It won't cut though steel armor but it will do a lot of damage to steel armor. Note however you will need some kind of enchantment to keep the blade from breaking while it is being made, the largest obsidian blade ever made was only about two feet long.

But forget swords use it to make spears and arrows, things that rely on piercing. You get a spear or arrow that barely notices flesh, cloth, or leather. It will even preform well against metal armor, not magically well, but it will routinely pierce it, A spear will reliably pierce chainmail and thinner plate but likely not a the thick steel of a breastplate. A spear or arrow made this way would go a gambeson or modern Kevlar with no noticeable resistance. If the enchantment strengthens the shaft it will be superior to even modern ones. Although you will want to use Japanese style bow drawing instead of European, the flexibility of the arrow shafts is far less important with a straight release path.

Diamond does have its uses however, it will let you make swords as sharp as normal swords that will basically never dull. I would expect to see more use in industrial settings, like axes and chisels. Of course if you can overcome the manufacturing problems with diamond, say with magic, you can make something just as sharp than obsidian, but not any better.

Note you will never get something sharp enough that a human swinging it can cut though a thick stone a pillar, they just cannot generate enough force to separate the material.

Paper is basically useless for weapons, you end up with something as strong and sharp as steel blade of the same dimensions, which will be too weak(floppy) or too dull depending on how you make it, paper mache might make something usable but it will dull very quickly. It make for some excellent saws and springs however. The enchantment will be useful for making tools and weapons from wood as well, carve from wood, enchant, and you have an axe or sword as good as steel but lighter for far cheaper. It will be dull before enchanting and passable after.

Honestly the sharpness enhancement is almost more useful for strengthening things.

Armor is where it will shine, I should mention paper armor was already workable, but with this enchantment you can make armor as good as plate from paper, leather, and cloth. Paper will have to be very thick paper, or layered and glued to be useful, but its fairly cheap to do. probably cheaper than leather or cloth. Basically you can paper mache armor shapes and enchant. Really useful for helmets or anything else that needs a strong curve. As a bonus it will be a lot lighter than steel. One thing you will have to worry about is the edges of your armor will be very very sharp unless they take the time to roll over the edges before enchanting.

enter image description here

enter image description here

  • $\begingroup$ Very thorough and thoughtful answer, just what I was looking for! However, please note that Sharpened items stay sharp, they don't wear, blunt or dull. $\endgroup$
    – Alendyias
    Commented Apr 19, 2021 at 16:57
  • $\begingroup$ @Alendyias that was unclear you said that but followed it up with saying the objects too soft or weak to hold and edge it becomes as hard and strength as tempered steel, tempered steel dulls, chips, and rolls. So you might want to clarify that. $\endgroup$
    – John
    Commented Apr 19, 2021 at 17:27
  • $\begingroup$ I have, thank you for informing me of the problem! $\endgroup$
    – Alendyias
    Commented Apr 19, 2021 at 17:29
  • $\begingroup$ @Alendyias made a few corrections with the clarification. $\endgroup$
    – John
    Commented Apr 19, 2021 at 17:41
  • $\begingroup$ Oh lord the aztecs. oh no. $\endgroup$ Commented Jun 1, 2021 at 17:32

You seem to neglect an important factor: a good cutting edge is always a compromise between cutting capability and durability.

The two properties usually conflict with each other, and any manufacturer has to find a compromise.

In this case if the edge is made sharper (with a much narrower angle) it will also become blunt faster, because it will have less material to apply resistance to the forces involved in cutting.

  • $\begingroup$ It doesnt actually blunt period. $\endgroup$ Commented Jun 1, 2021 at 17:32

This largely depends on how it works, if it is more conceptual and magic in nature, that is, increasing cutting capacity without thinning the edge, it would be very effective, as it would allow an edge to cut well but not dull as fast as something else with that level of sharpness.

If it does decrease the width of the edge, which is what sharpness operates like in our world, this would lead to it simply acting like a sharper blade, and would thus begin to dull faster. But you already addressed this in your question.

So, in your scenario, where it gets sharper but isn't able to dull or chip, you would just have impossibly good blades, which already have one of the biggest issues with very sharp blades dealt with.

An answer to question one, perhaps a sort of steel-lithium alloy, which would help making it lighter than pure steel. This lightness would help make it easier to start and stop motion, and be less tiring to swing about. The issue with fragility and lack of pressure would be solved by the enchantment. More generally, just go for very light blades.

  • $\begingroup$ This is a very well-stated question, good job starting strong! Yes, the Enchantment increases cutting capacity without thinning the edge, and I didn't think about how light blades would be benefited by Sharpen's strengthening effects. Out of curiosity, how viable is a steel/lithium alloy? All I know is that lithium is extremely light and reactive.... $\endgroup$
    – Alendyias
    Commented Apr 22, 2021 at 13:16
  • $\begingroup$ I did not think of the reactivity, that would make it an issue. I would have to look into that. $\endgroup$
    – Zoey
    Commented Apr 22, 2021 at 16:17

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