Do you know what Blood artist does?
Blood artist triggers all at the same time as everything else dying. With a full board at late game, I'd be at the advantage because either with killing wave, he'll be forced to keep SOMETHING on board and thus will pay the life while I sack all my undying creatures/gravecrawlers and force him to lose life while gaining life.
5 life doesn't mean anything when 9 or more creatures die. I get the net gain of 9 while he only gets to offset 5 of that.
Running burn spells and tragic slips also helps, because after everything resolves, I can just give his dinky beast token -13/-13.