Taborax has lifelink as long as it has five or more +1/+1 counters on it.
Whenever another nontoken creature you control dies, put a +1/+1 counter on Taborax. If that creature was a Cleric, you may draw a card. If you do, you lose 1 life.
Taborax turns dying creatures into card advantage and a growing flying threat. Sacrifice fodder and Clerics all game to draw cards and stack +1/+1 counters, then close with an evasive lifelinking beater or a sacrifice-fueled combo. You operate as a grindy mono-black aristocrats deck that out-resources the table.
Built-in card advantage engine that mono-black otherwise struggles to find
Cheap 3-mana flyer that snowballs into a real evasive lifelink threat
Rewards sacrifice synergies you'd run anyway, plus a Cleric tribal payoff
Mono-black gives access to powerful tutors, ramp, and recursion
Card draw costs life and requires creatures actually dying, so it can be slow without enablers
Removal-heavy tables can repeatedly kill Taborax before counters accumulate
Single-color means no access to interaction outside black or efficient combo pieces from other colors
Relies on a critical mass of cheap creatures and sac outlets to function