Obi-Wan, Negotiator

Protection from Assassins
Other Knights you control get +2/+2 and have protection from Assassins.

When Obi-Wan, Negotiator enters the battlefield, for
each opponent, exile up to one target creature that
player controls until Obi-Wan, Negotiator leaves the battlefield.
—
Obi-Wan, Negotiator is a proxy of Haytham
Kenway.