Aye, found a sweet lil glitch.

If you want to do a new pvp character:

-Aqcuire boss soul (Any boss soul)
-Equip
-Do an r1 attack
-Shortly before the animation ends, press X then immediately start
-Use Estus flask
-If done right, it will now ask you to consume boss soul
-Boss soul will be consumed, but is still in your inventory

You can repeat that as much as you want, there is no limit. Same goes for fire keeper souls. ALL the humanity.

I'm level 110 now.