Kenrith, the Returned King

Legendary Creature — Human Noble

: All creatures gain trample and haste until end of turn.

: Put a +1/+1 counter on target creature.

: Target player gains 5 life.

: Target player draws a card.

: Put target creature card from a graveyard onto the battlefield under its owner's control.

Kenrith's last ability can target a creature card in any player's graveyard. Its owner will control the creature, and it will remain on the battlefield even if you leave the game (if you don't own it).
Kenrith's first ability affects only creatures on the battlefield at the time it resolves. Creatures that enter the battlefield later in the turn won't gain trample or haste.