you [might] have to go deeper in the forest and go l l r l  and there will be a strange man who wants a glowing key then go  r l l l  and into the shack take  the key and return to the man after  that you fight him

but how do i fight him

You have to do the following things to get the funx3 ending. Firsts, go to the  haunted forest, then go deeper, you then must go in the following order left, left right, left, after you encounter him but not fight him yet, do the actions  when you go deeeper again, go right, leftx3 then you fight the jevil thing. what happens next i will let you find  out

i did it! here is how i did it, its REALLY HARD llrl, to go to the fun guy, , then go get the key from rlll then the fight begins, press act and use heal and tire abilities, make sure you heal enough! despite him getting ubsurd helth, he will tire out, when he is, spare him, you will get you items and shard, ice, head to town and steal from the smalll shop for gun and rubies, then kill the dealer in dark alley, you will get teh other key, go to shack and kill moth, then go in basement and use shard on demon, there you go!