User blog comment:Jopjopjop/Volume 20 Spoilers/@comment-3965848-20150720134401/@comment-141.135.80.110-20150720134911

Vali's absorb has a cap though and that has been shown multiple times.

He cannot absorb more power then his current limit any excess energy/power gets difused/released through his wings.

Actually trying to do this could kill him because his body would not be able to hold or difuse it.