I started with what I liked about Sejiri Merfolk, then built around unblockable and first strike, with some enchantments thrown in for good measure. I am really getting attached to Ethereal Armor in decks of this kind, as being able to give a boost as high as 11 in this deck is pretty significant for one mana. I limited the number of non-plains white-mana lands so I could improve the chances of getting the abilities on the merfolk. The 21/11/8 curve is perhaps too cheap at 1.68, however.