For my tastes, as guidelines I think are worth sticking to, a keyword mechanic needs to be doing offloading in the rules text that makes things more convenient , it needs to have human-understandable reminder text that isnt just the rules text written out, and it needs to be something that other things can usefully reference
While the character I'm about to show you is an old favorite, the card itself is a brand-new design
But Emrakul, the Promised End is easier to cast, not banned in Commander, and can sit at the top of Eldrazi ramp strategies, reanimator strategies, and even Birthing Pod setups
But there are some limited production booster boxes that might be worth a look
Aristocrats arguably have more than enough Blood Artist effects, but Susurian Voidborn makes a strong argument for inclusion
1 Read the Bones