With a quite useful Stormruler, you may think its lame (probably not). If you don't already know this, pay attention. Grab a Stormruler, (the sword, the one that looks like a unicorn's horn) and go to Storm King Archstone. Soon as you enter the stage, turn around and run straight forward. Take a right. And go inside the smashed building. Once inside, go to the RIGHT corner, not the left. Stand in the corner and two-hand Stormruler. Lock on, and your tornado thingy that spins should murder the flying manta thingies. Have fun with your unlimited souls :D
Normally up to 18,000+ souls per visit to the fabulous shrines with a Ring of Avarice :P
WARNING: Side effects may include: SL712idus, explosive fart, and obsession with fish (especially flying fish).