Waverlyde, Nolva's Consort

Signature Spell (This spell can only be cast from
the command zone if you control your commander.)
Soulbond (You may pair this creature with
another unpaired creature when either enters the
battlefield. They remain paired for as long as you
control both of them.)
As long as Waverlyde, Nolva's Consort is paired
with another creature, each of those creatures has undying.