Thaddeus, Peace Keeper

Partner with Lavin, Azorius Arrester (When this
creature enters the battlefield, target player puts
Lavin into their hand from their library, then shuffle.)
Whenever Thaddeus, Peace Keeper blocks or
becomes blocked by a creature, you may detain
that creature, if you do, Thaddeus, Peace Keeper
and that creature deal no combat damage this
turn. (Until your next turn, that permanent
can't attack or block and its activated abilities
can't be activated.)