Finally hit on a PvP team that seems to be working -- Ghost Rider and Blaster White Crown Phoenix.
I was enjoying Infiltrator Jean, but she was getting murdered by every Ghost Rider that came along. Blaster Jean is a little vulnerable to all of those Tactician Emmas, but she's also strong against all these Bruisers who keep coming up.
Add a little Scroll of Hegolob at the right time to nullify those pesky Quicksilvers and Valkyries and you're in business.
By the way, the M:AA wiki is suggesting that the amounts of Gold to "Reforge" weapons are on a variable cost plan, like Deadpool, so if it seems too high to you, don't pay anything yet.