The Soul Stone is a black legendary artifact, and the other Infinity Stones will almost definitely come in Red, Blue, Green, and White versions
The more you grow H&A, the more counters you get to stack on other creatures each combat, so you can make two or more sizeable threats at the same time
Repeat this process for first strike, double strike, deathtouch, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance
By having the cards ready, you can immediately start testing new strategies and combos once the set is released
I think that a rising tide lifts all the boats and so well see versions of Miirym break $5
We can expect these Ikoria promos to remain in chests until the release of Core 2021 , and likewise for future sets