Hmm here's some ideas off the top of my head.
The obvious thing would be the Elena heal hyper.
Maybe give herself a shot with a syringe so she can heal a little slowly. Like Gutsman does?
On the flip side give player two a syringe to do damage, or a poison over time.
A level 3 hyper where she gets a and extra new full life bar.
Bandage to heal herself some.
A life steal move where she takes life from player two and gives it to herself.
Power drain then shoot it back.
Throw a bucket of Hydrofluoric acid to do some damage.
Some type of Anesthetic to slow down or put the enemy to sleep / freeze him for a second.
Surgeons use lasers for surgery. That would do some damage.
Dentist drill?
Medical tools and knives.
Drop a package that could float around the screen randomly that either player can pickup to heal slightly. Or perhaps it could take a few hits to open like the smash brothers ultimate ball that floats around.
Hacksaw for those limbs? Old school hand drill?
X-Ray machine? Maybe draw a few skulls and it could be placed on player 2 while it's in use and do some damage. It would be funny to see player two running around with the skull covering ther head for the duration of the move.
Put a cast on player 2 as a helper and maybe disable one of their moves for duration that the cast is on them?
Whelp I'm out of ideas.., maybe something here will help.
Edit:
Like mentioned above with the floating healing pack. It could also go the other way and do damage. There could also be a random one where you don't know if your gonna get healed or take damage until you get it.
April Fools