Rey and Harmony, Elf Couple

When Rey and Harmony enter the battlefield, target creature your opponent controls cannot attack during combat phase.
{2}{g}: Target creature cannot be blocked this turn. This can only be played if you control three or more elves.
{2}{u}: Target opponent reveals their hand and discards all instants in their hand. Play this only if you control a card named Miya, The Elf Queens Sister.