Bitterblossom

At the beginning of your upkeep, you lose 1 life and create a 1/1 black Faerie Rogue creature token with flying.

Have

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Sol Ring

Bitterbloom Bearer

Flash
Flying
At the beginning of your upkeep, you lose 1 life and create a 1/1 blue and black Faerie creature token with flying.

Sephiroth, One-Winged Angel

Flying
Super Nova — As this creature transforms into Sephiroth, One-Winged Angel, you get an emblem with "Whenever a creature dies, target opponent loses 1 life and you gain 1 life."
Whenever Sephiroth attacks, you may sacrifice any number of other creatures. If you do, draw that many cards.

Sephiroth, Fabled SOLDIER

Whenever Sephiroth enters or attacks, you may sacrifice another creature. If you do, draw a card.
Whenever another creature dies, target opponent loses 1 life and you gain 1 life. If this is the fourth time this ability has resolved this turn, transform Sephiroth.