I suppose Electro tanks most of the colours for your situation? I've never thought of maximising (50%) her damage reduction.Electro/Onslaught/Carnage does sound fun. I don't have Killmonger champed, so I can't do much.
So, your idea is another way of looking at how to build teams around her, which I've never look at. I'll see if I can create something else using the idea of maximising her 50% damage reduction.