The term "defending player" in the myriad rules (or any other ability of an attacking creature) refers to the player the creature with myriad was attacking, the controller of the planeswalker it was attacking, or the protector of the battle it was attacking at the time the ability resolves
I hate Koma with a fiery passion
Hats off to Glenn Jones and his team at WotC for these powerful and dynamic commander options
If you just want to learn how to play, the Starter kit is an excellent collection of two decks, a guide on how to play Magic, and even codes to redeem both decks on MTG Arena
There arent many ways to gain life in this deck, but Aerith Gainsborough can still be a powerhouse if you move counters onto her before she dies
I know you most likely wont use that graveyard exile on yourself, but having the option to make a Zombie and draw a card at the cost of getting rid of an unneeded card in your bin isnt too bad