Generally the merc shouldn't be all that strong, like maybe just doing 10% of what the player would be doing with an optimal/suboptimal loadout, he's there just mostly making you feel like there's more than YOU in this world which fights i would certainly love if this merc would be like the ones in fire emblem, meaning they get new weapons and better stuff as the game goes on, skills and everything. The AI should be very simple and cycle between damage and healing, the merc would just use swords to attack the boss there, every 60 seconds the merc would run away from the boss for a little bit and heal up This NPC would use melee weapons as their main weapons, in hardmode gaining the use of perhaps some new weapon classes like bows or adding projectile swords to their arsenal Skipping bosses (going straight to skeletron and skipping deerclops/queen bee) would increase the the price by however many bosses were skipped (in the earlier case it would be 2 bosses skipped and 1 new boss defeated, +15 gold to original price)

at the cheap price of 10 gold per boss fight/his lifeĪfter defeating a boss (that isn't EoC/slime), the merc would raise his price by 5 every time

The mercenary NPC (merc for short) would be the first and currently only, fully combat focused NPCĪfter defeating king slime and/or eye of cthulhu, the merc will be able to move into the town offering help for your future boss fights.