TEMPORAL TRESPASS A nice reprint here for people that like extra turns
Therefore, why would I do that with Petilil when I could do it with Mew
1UBRLegendary Creature Human Noble Villain Whenever you discard one or more land cards, each opponent loses 2 life
Whilst you're doing these solo gates, you'll also unlock more structure decks, cards, and gems for purchasing card packs, the last of which you'll need later
Other prominent mechanics that incorporate (or freely enable) sacrifice include: Food, Clues, Treasures, Sagas, Unearth, Encore, Evoke, any other temporary tokens such as Faerie Artisans or Hostility, cards with Upkeep, Quests, Exploit, Casualty and now Bargain
It's a variant on the level up mechanic that uses triggered abilities instead of mana payment to level up