never thought i'd see you here again, slymash
yeah, the eye is the easiest especially if you have shurikens, but don't even try anything else :v
This is where i think you are wrong, the easiest boss is Slime king, the easiest boss to summon is the eye.
but i prefer to build for every boss a little arena too, so no night zombies comming and kill you, or in the corrupt these flying things..