Seris, Celestial Overseer

+2: Create a white, blue and black enchantment token named Nebula. It has "At the beginning of your upkeep, you gain 1 life."
-1: Until your next turn, Nebula tokens you control have "Sacrifice this permanent: Draw a card, then add one mana of any colour."
-7: Draw a card for each enchantment you control, then each opponent discards a card for every two Nebula tokens you control.