The steady life drain from creature deaths adds inevitability, especially in sacrifice or aristocrats shells
First, whenever a creature you control dies, each opponent has to exile a creature of their own--this reminds me of a card like Grave Pact, only better because the casting cost is two Black versus three Black and exiling is better than sacrificing
Morphling was very powerful when it was printed and Aetherling had its time in the sun in Standard, despite costing 6 mana
There are infinite combos that outright win you the game, like with Walking Ballista, but Heliod can be a centerpiece of devotion decks, +1/+1 counters, lifegain decks, and enchantment-based decks
Kit Cloudkicker, Navigator One high-flying Lorcana card Kit Cloudkicker, Navigator may initially seem like a Lorcana card that isnt that great