- Create a legendary 4/4 blue and black Dragon creature token with flying named Scarzam's Dragon.
- Return target nonland permanent to its owner's hand. That player discards two cards.
- Destroy target creature dealt damage this turn. It's controller loses 5 life.
- Until end of turn, Archers you control gain haste and "When this creature dies, you may return it to your hand."
- If you're the monarch, each opponent sacrifices a permanent at random, then draws a card. Otherwise, you become the monarch.
- Create X black and green Insect creature tokens, where X is the greatest number of cards in an opponent's hand.
I think here's plenty more legendaries that could benefit from cards like this. Feel free to post some of your own!