Invasion of Theros is a battle that can tutor gods, among other card types, and transforms into Ephara, Ever-Sheltering if the battle is defeated
Fearow can be obtained from Wisdom of Sea and Sky: Ho-Oh pack in the Wisdom of Sea and Sky set
Cards like Ponder and Preordain will regularly be good enough to justify their presence in a deck, but playing too many of those kinds of cards will have diminishing returns
Not only does he come down early and buff your subsequent Samurai with haste for just one mana, but he can also create on-rate 5/5 flyers for five mana if youre attacking with a modified creature: a condition which, given their non-literal affinity for equipment, is incredibly easy for a Samurai deck to satisfy
There's also a sub-theme of creatures with toughness of one, since Zinnia gets a buff from the more creatures you have with a toughness of one