Figure has taken down a lot of games in his time, some as a mere 2/2, some as a 4/4 and some as a terrifying 8/8
Well of Lost Dreams then lets you dump mana into it to draw cards equal to the amount of mana you spend, up to a max of the amount of life you gained
Flickering it or copying it gets you even more cards, you can sacrifice it to Flare of Cultivation or Grist, the Hunger Tide, and sometimes it just enables a double block
Theres no better color combination to make this deck, either, given how busted Temur energy decks were in Standard back in the day
There are also tons of creatures that arent changelings but provide useful abilities like creating Treasures with Magda, Brazen Outlaw, granting islandwalk from Master of the Pearl Trident, or making each other creature indestructible with Knight Exemplar