Aether for F! Grima good?

If you are running something that lowers special cool down

Eeeeeeeh maybe?

I haven't had her for long but in my experience, F!Grima really needs a useable special. Her attack stat isn't particularly amazing all by itself. Having access to burst damage increases her usefulness by a lot.

If you have her with +ATK, you might be able to try heavy blade seal + class buffs to make Aether work, but I otherwise I don't think it's viable.

I'll probably use Aether for Tempest Trials or anything similar where sustain is important. However without anything reducing cooldown on Specials, like Steady/Warding Breath, then it's better to use Moonbow/Glimmer for short matches.