Idk if this is smart or not but im thinking of using a lot of doing a voltron thing. 7 power is a great floor for power cause you only need to hit 3 times. Just copy an unblockable like Slither Blade to swing as an unblockable and try to use +1 counters or even stuff like Thornling/Aetherling/Endling to pump him up for bigger damage. The lings also have protective abilities too.
BChainer, Dementia Master(Big Mana/Reanimator)
BRRakdos, The Showstopper (Mass Life Loss/Ramp)
BUThe Scarab God (Zombie Tribal/Control)
BWKarlov of the Ghost Council (Life Gain)
BGJarad, Golgari Lich Lord (Stompy/Dredge)
BRGProssh, Skyraider of Kher (Tokens/Non-infinite Combo)