Ruby has been the yin to Amethyst's yang, the two inks teaming up to create the best deck in the game throughout much of Rise of the Floodborn
If you need it, then you need it
8 Sisu, Divine Water Dragon (Enchanted) The Answer To Sapphire's Prayers
Its still costly to actually cast the creature when the time comes to do it, plus having to bolt yourself for an untapped land is a high cost, so Im not quite on board with full-on staple status for this MDFC
The cast trigger helps to peck away at opposing life totals while you control the board, and it becomes a win condition with a variety of infinite combos
As for the rest, we're looking at the natural design trend we've been seeing ever since Dark ConfidantDark Confidant: Creatures are easily removable, so it's easy to put powerful card advantage mechanics on them for cheaper than you'd see them otherwise