Battlebond

When Battlebond enters the battlefield, choose a creature card name. Creatures you control have partner with the chosen card. (When they enter
the battlefield, target player may put the chosen card
into their hand from their library, then shuffle.)
{g/w}{g/w}, Sacrifice Battlebond: Target creature gains soulbond and "As long as this creature is paired
with another creature, each of those creatures
gets +2/+2." (This effect lasts indefinitely.)