Rework undraw

[Allegor]

Undraw should sacrifice card drawn to give Ast 1k mp back.

I second this, buff the useless button to make it give a much needed MP regen skill, it's a win win. Maybe give it a 60s cd so it aligns with Assize, Aetherflow and Lucid.

In the old system Undraw would throw away useless cards, but in this new system no card is useless, so it leaves you with the choice - do I wanna buff someone, or do I wanna regen some MP - much like SCH's ED.