Set in the 12th century C.E. a trend seems to spread like wildfire across the kingdom: many young mages are practicing sealing a slain magical creature into all kinds of melee weapons, most commonly a broom, as a bronze sword is considered a luxury.
The seal will bind the magical essence of the slain creature to the artifact and imbues it with a magical property, occasionally two. The magical properties can range from spitting out a fireball to casting an area-of-effect spell such as blizzard.
Contractual summoning is different as there is no material or any item involved. In order to perform a summoning the user must go through a tedious ritual to form a pact with the magical creature, usually one much more powerful than those found around the kingdom.
I often wonder, given the incredibly low rate of success for contractual summoning, why do so many veteran mages still prefer this method rather than simply sealing a slain magical creature into a weapon?