@Tatsuya
My boy.
In ds1, pyromancy does flat damage, regardless of level.
In 2, it had int and father scaling, but nothing to pump it more
In 3:
40 INT
40 FTH
Rings for a 45% damage increase.
Leo ring: 30% counter DMG increase. Since the lava from great chaos fireball counts as counter DMG. That's a lot of fucking damage