ah yes, a real dumpster of a collection here. when i think of terrible champions, my mind immediately leaps to such trash as dazdurk, ixlimor, lix, maneater, peydma, and ursala. how i rue the days when i opened a new shard full of hope and expectations and pulled such flotsam as deacon, drath, stag knight, magnarr, gorgorab, miscreated monster, or doompriest. at least on those unhappy occasions, i can be thankful that i haven't had the misfortune to get saddled with a sethallia, a rae, or, god forbid, a seer in the way that you have.
in regard to cb, you can make an unkillable team with warcaster and maneater plus 3 dps champions, or 2 dps champions and apothecary/high khatun if you can't get maneater to stupid high speeds (i think 292 is the magic number). Skratch has a few videos on the subject and deadwoodjedi has the info you need for all manner of unkillable comps on their site. the one i mentioned above is slow tuned man tower unkillable.