I’ve seen over half a dozen design for Kerrigan Mercy. Though this D.va one I think is awesome. It could borrow out of the ground in front of her instead of warping down from… you know the mech storage in the sky…?
This is my favorite version (I have a weakness for purple) for mercy.
https://www.deviantart.com/imdrunkontea/art/Infested-Mercigan-748134845
I have to admit I’d play D.va more. I personally dont care for the teenage mech piloting pop star act. If they made her into a zerg though your playing hard on my starcraft weakness. Even better if they had new voicelines.
I personally always thought Brigitte be a good Kerrigan crossover though.
I get mercy and pharah are obvious choices cause “wings” so they get all that kind of stuff. But Kerrigan doesnt really fly. Brigitte would work better because the wing tentacles could act like her kit.
Primary attacks - would be her lashing with the wings.
Whip Shot - would be and extending tentacle stab.
Barrier & shield bash - she could put them in front of her and use them as a shield and it makes sense they would help her “bash”
Armor pack - could be a Psionic Blast or Zerg Sludge
Rally - Would be a Kerrigan gethering her swarm for the attack 
Brigitte 4 Infested Kerrigan I say WHOS WITH ME!!!
My Eyes!!! twenty characters
DaQUEEN
To op, it would break game not internet.
Nerf it before its even out!!!
OH NELLY
TOTALLY NOT BUMPING THIS THREADYOU ARE A BLOODY GENIUS
mate
Totally called School girl D.Va