I wish Summons became spells in 5.0

[Jandor]

Personally I'd rather see SE take a similar approach to Bahamut and make all Egi cast spells based on what the Summoner was casting, but I understand that would take a lot of work so I'm not expecting that to happen anytime soon.

I don't think it would take too much effort, depends how extensive you want the revamp to be though.

You could make the egi's function similarly to demi-bahamut on a basic level easily enough.
Cast Summon 1, 2 or 3 to have your egi hovering over your shoulder automatically throwing windblades/big rocks/fireballs at whatever target you're attacking.