I have some ideas for a type of skill called "hero skills" which are like ranged-only skills but only work for one hero and only appear when you using that hero. here are some ideas
Frenzy dash:(Rare) (Can only be used by soldier): When frenzy is active gain some temporary stamina.
Longblade:(Rare) (Can only be used by Knight): Increase the range of your attack but decrease speed
Berserk: (Legendary) (Can only be used by Soldier): Frenzy's cooldown is decreased by 10 seconds