Plot hole! Hiruzen having Enma

[VongolaX]

Amaterasu isn't a summon.... It causes stress on the eyes which causes them to bleed

itachi summoned crows

 

[phantomlord22]

the rules for summoning are made by kishi
then he is totally aware of it more than all of us
If he says an edo can use blood and summon things, then It's a manga fact