What ability would you like to see added for your Job in the Expansion? (theorizing)

[Ashrak]

Double Cast: Swiftcast now allows you to instant cast twice in a row; first spell outside of GCD.

Please no. I'm using Swiftcast almost exclusively for Thunder 2/3 and doublecasting this is pointless.

Oil (Off-GCD): Places a debuff on the enemy that increases Fire Damage dealt by 10%

Sounds good.

What I would like to see in the next expansion?

Prefer two off-GCD abilities like Manawell (for the next 15 seconds, your spells cost no mana. High cooldown, such as 3 minutes) or an "You can cast up for the next 10 seconds while you move"-Ability.