Had this same idea. 3 different modes, one like rumble and just legendaries, one a fusion of rumble and elimination with exotics, and one like the last one except killing increases damage by 25% (for last two modes, it should take 3 hits to kill at base damage) with the 4th kill granting a 100% bonus(1.5 hit kill), and at the same time, a decrease in defense by 12.5%, with the 4th kill granting a 50% decrease, to make it fair for the last other person alive, assuming they didn't get any kills. Killing someone with kills grants you their buff/debuff plus the extra. This last mode should work somewhat like trials, with scorecards, but a little lenient, since there are no teams. Edit: bolt-caster throwing attack should be nerfed for sword modes only. 2 hit kill. (One with buff) Edit 2: No tracker. Edit 3: First mode, infinite ammo. Second, more frequent ammo drops. Third, one drop.