Flash (You may cast this spell any time you could cast an instant.)
Royal Guard — When Thancred Waters enters, another target legendary permanent you control gains
indestructible (Effects that say "destroy" don't destroy that permanent. An indestructible creature can't be destroyed by damage.) for as long as you control Thancred Waters.
Whenever you cast a noncreature spell, Thancred Waters gains
indestructible (Effects that say "destroy" don't destroy that permanent. An indestructible creature can't be destroyed by damage.) until end of turn.