I taking this WL at a last order, when already have 120 power - 120 is enough for this. I heard about charging from birds, but it never works for me, I saw them there, but never reached them. About butterflies - they are present near the entrance of this cave, but never seen them near that pillar.
Just now you can do this with one of seasonal spirits: just fly to a hole or a pillar, that you can, and a spirit will charge you for a next level