Frieren, The Slayer

Flying, first strike, vigilance, trample

At the beginning of each combat, until end
of turn, each other creature you control
gets +1/+1 if it has flying, +1/+1 if it has
first strike, and so on for double strike,
deathtouch, haste, hexproof, indestructible,
lifelink, menace, protection, reach, trample,
vigilance, and partner.

Partner