I know it is already too late, but I haven't been around for quite a while and decided to post it anyway, maybe you'd like the ideas so why not. I have two ideas for a shield, both working in a similar way.

1. Black Hole Generator
Visuals:

Shield body: Rabbit would be covered with a dark sphere, maybe it could even drain the light around it a bit.

Projectiles: It would leave an lightless points behind the rabbit, staying in one place similar to how TNT works. It would be rather an ambient lighting effect rather than any graphic by itself.

Particles: Sparks when something hits the generated hole.

Shield Monitor: Thats actually incredibly hard to come up with anything than just a dark monitor without anything on its screen. Maybe I'll get a better idea later.

Mechanics:

Projectiles: Instead of actually damaging anything, projectiles(which aren't really moving at all) would suck any projectiles nearby inside it and immobilize them, maybe except for homing projectiles like seekers that would be immobilized only temporarily. Black holes would dissappear after a short time. I'm not even sure, but I think it might be a good idea of making it suck both your and your enemies projectiles. And, it might have an interesting effect with TNT when it sucks it in.

Shield: Because of defensive nature of the shield itself it might have been a bit overpowered while working as a normal one. I thought it might be a good idea of it having shield hearts(that would make it dissapear after getting hit once or twice), or maybe shooting projectiles would drain its time left. Actualy, it might not be that op when its only for 15 seconds.

I have no ideas for the sounds right now, maybe I'll think of something later.

2. Tornado Shield
Visuals:

Projectiles: Small cyclones or actually anything that spins around. There is even a spinning animation of something inside the jj2 that plus uses as an bullet animation for some weapon, though a circle-shaped tornado of some sort would be much better.

Shield: Shape wouldn't be a sphere - near rabbits feet there could be an spinning animation of cyclone.

Shield Monitor: A small tornado on the screen.

Mechanics:

Projectiles: I have three thoughts how this might work:
- Projectiles would suck rabbits in immobilizing them and not damaging, and when the tornado runs out it would throw them in random location. Tornados would stay in one place maybe moving around a bit randomly,
- They might either be a homing projectiles and damage rabbits as they touch them,
- First idea, but damaging them and not throwing them away randomly.

Shield: Might speed up the rabbit or increase its jumping height, though not necessary.

Sounds:

Looped Sound: Maybe wind one? Because why not.

Projectiles sound: Maybe also wind sound, just changed a bit so at the beggining when you shoot its louder, and then constantly it gets more quiet.

Both are about sucking, I know.