It makes your dragons indestructible and slowly builds up +1/+1 counters based on their colors
Sample Decklist This deck is designed for Bracket 2 (Core) , but can keep up with low-end Bracket 3 (Upgraded) decks
There are some strategies which can encourage a player to fall into the trap, for instance by banishing their glimmers when they are running an ink-heavy sapphire deck
Sea creature decks love it, but so do toughness-matters decks like Arcades, the Strategist, The Pride of Hull Clade, Phenax, God of Deception, and Plagon, Lord of the Beach, to name a few
Chances are that casual lifegain Commander decks will just run both of these abilities