While this is a welcome ability in and of itself for the sake of widening your board state, it also doubles any ETB effects and provides opportunities for additional activated and triggered abilities
Durnan uses a new mechanic in the Battle for Baldur's Gate set, which will be familiar to D&D players: Backgrounds
Commanders like Marwyn, Lathril, and Voja give players various win conditions and mana generation options
As the King of Games and Egypt's former pharaoh, Yugi is the only one that can handle their power
Dragon Shrine has a simple effect that lets you send a Dragon from your deck to the Graveyard, and if you sent a normal monster you can send one more Dragon monster too
Theres a distinct economy of wants/haves that can be explained only by being involved in the system itself, but Ill try my best to get you clued in before you feel lost