At its core, Mutate is a modal mechanicyou choose between a creature and an aura-like effect
When that creature attacks in concert with another boasting a higher power, Training triggers and grants it a +1/+1 counter
The alternate artwork in Genetic Apex clearly emphasizes this fact, showcasing Rapidash galloping across a flower meadow so quickly that numerous petals billow around it
Megara, Secret Keeper, on the other hand, is an early game card with a cost of three that gains the ability to force the opponent to discard a card when she is challenged once boosted with a card underneath it
If you want sagas, I think you want access to all 5 colors from Tom Bombadil, but I can still see this being potent if you have a way to speed through sagas quickly
Academy ManufactorAcademy Manufactor (147,608 Inclusions, 4% of 4,046,881 Decks) Amazing as Academy ManufactorAcademy Manufactor is getting for Treasure and Tri-Token decks these days with all the new Clue, Food, and Treasure support, that's just not what we're doing today