>>12048891You need to use your gun, evade and all the other special options besides default attacks more often in every battle.
I actually bet the rabbit on my first try playing the game and didn't knew what to do till I tried suicide runs in directions I already suspected to kill me. You can try leveling before the boss, at the few enemies in the room before it; you can kill the rabbits; you can open the door with a master key and try to kill the enemies in the first room, but don't enter the middle building.
Also like you have already seen with 0 sen there spawn glitch enemies which seems to be OP, but they actually aren't. They drop like 10000 souls which is somewhat cheating so early.