Celestine Cave Witch

When Celestine Cave Witch enters the battlefield, create two 1/1 black Insect creature tokens.
Whenever Celestine Cave Witch attacks, you may sacrifice an Insect. When you do, curse defending player. (Create a black Aura Curse enchantment token that's attached to that player. It has enchant player and "At the beginning of your upkeep, you lose 1 life.")