Atk/Spd link candidates?

Probably fast units that can access Desperation weapons as they wouldn’t need Desperation because it’s the weapon skill. So speedy Blue tome/Dagger/Bow unit’s.

Firesweep weapons are good as well.

I would put it on a unit with good defenses but lacking Atk/Spd and Smite them into a group of enemies for easy KOs.