If one other Merfolk is tapped, Kumena can't be blocked that turn, allowing it to reliably deal commander damage
This demon goes straight into your graveyard if you want, and some mechanics work best when you have a big-power or high-toughness creature in your yard
For those not in the know, Abdel Adrian and Sarevok were the hero and villain in Baldur's Gate 1
EDH is a format with higher life total, more opponents, and much longer play times than normal duels, and so it makes total sense to infuse your massive decks with as many potent cards as possible to help you while still ensuring the deck can actually function
I walked over and grabbed one of the playtest decks
These are three powerful archetypes by themselves, and treasure decks can make use of the best parts of each strategy