Neyali, Suns Vanguard Token decks need effects that boost the power of their 1/1s so they can win the game, and double strike is a perfect because it stacks very well with anthems
White weenie decks don't really have a use for all that extra mana should they fail to Armageddon, so trading two mana for one more point of damage each turn stands as a pretty fair bargain
Lets dive into these must-have cards
Because you just need treasures from any source to buff creatures, this gives you a ton of options with combo potential, especially with Mari and cards like Deadly Dispute or Academy Manufactor to increase the value of all of your various effects that rely on treasures
If we think about creature auras using quadrant theory, enchanting your own creatures is something thats great when youre in a winning board state, reasonable when youre at parity, risky during the developing turns of the game and actively bad when youre behind