They say that the best weapon is the weapon you don't need to fire or you only need to fire once.
Firepower has always worked as a deterrent... but why is it so effective and how can you employ it the same way in a medieval fantasy world without the direct use of magic?
The adversary is an empire with known land superiority over any other sovereign that can muster more than a million professional soldiers of its own, 4 million levies and another 2 million mixed of professional and levy soldiers from its vast vassal states. Economic wise, they are very sufficient and can maintain a standing army indefinitely. They also deploy land battleships with no gunpowder but with numerous ballistas and formidable magicians that serves as the battleship's main weapon. The empire is not festered by corruption and uses divide and conquer tactics to subjugate adversaries.
The smaller kingdom
The other country is a kingdom protected by mountain ranges and known for its formidable and numerous: dragon knights, wyvern riders and griffin knights. The kingdom also have many magic knight orders and a well equipped professional army of 100 000 with an additional 400 000 levy that can be called upon but those are very ill equipped.
Slavery is allowed except for the beastmen confederation and dwarven communists.
- The hero can use magic, which is limited to time-space manipulation, rune crafting and spellarms. He is from our world and was whisked away but was prepared for it beforehand.
- He is a newly crowned baron of the border between the empire and the kingdom.
- He brought firearms and needs to demoralize the enemy and the whole world on the effectiveness of his weapons: "Peace through superior fire power."
- The goal is to shock and awe the empire without destroying their military in fear that the beastmen federation and dwarven communist would invade them.
- The kingdom must have a deterrent against any other foreign threats.
- This will prove the hero's usefulness to the royal family despite being a newly crowned baron.
I need the psychological aspect of this saying and be able to employ it at that situation.
I don't know if gunpowder firearms (Guns, howitzers, mortar, bombs and etc) will work as deterrent but I know mostly it won't.
I think flying ships will do (Kirov from C&C games) but I don't know how I will be able to employ that psychological impact with the flying ships.
If all else fail, I will have to resort to magic that employs matter/anti-matter reaction or matter to energy conversion and be done with it but that won't be fun to read.
I will take any suggestions!