When a persist creature dies with no -1/-1 counter on it dies, it returns to the battlefield with a -1/-1 counter
They are also strong at the ramping, and multiple one drop mana makers with no restriction on this break decks and formats, like Birds of Paradise and the Llanowar Elves speeding up Fires of Yayimaya to dominate Standard as a second turn drop
Once its become a planeswalker, you have more things going, like creating 1/1s and Disenchanting
Remove an indestructible counter from Myojin of Blooming Dawn: Create a 1/1 colorless Spirit creature token for each permanent you control
to ensure it has enough damage to finish it off.
Essentially, if you have a full party with all four of these on the board, you can pay one white, one blue, and one black mana to give the Warrior lifelink, deathtouch, and make him unblockable (deathtouch and unblockable at the same time has no real use, but thats still OP to think about)