You see, if you cast a spell that sets up an effect that happens "at end of turn" once you've past the start of the end-of-turn step, you can keep the results of that spell around until the next end-of-turn step
If a big creature-wiping spell is dropped you can sacrifice a tiny goblin to save your big guy, which is very on-brand for goblins
Me too, that's totally understandable
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
You may then have that player shuffle that library
This card could be end up staying at the head of the pack thanks to the (somewhat disturbing) trend of cards with girls on them fetching a lot of money on the Pokemon market