Focussing on sacrificing just about anyone and anything to achieve his goals, Sephiroth encourages you to keep sacrificing creatures to heal, deal damage, and draw, all to gain access to his incredibly powerful alternate form
However, if you cant immediately follow it up with tokens then its probably best not to play it as it will just get removed
If you control no creatures other than Joo Dee and no artifacts as the ability resolves, you'll need to sacrifice either Joo Dee or the token copy
Whether Warlock Class will see play outside of Virtus & Gorm and other decks that use Quietus Spike is debatable, but again I like it for Liesa because it comes down early, and levelling it up wont cost me life
The question was, black's rituals got moved off to redbut was it something black could do infrequently