Gwenevere, Shadow Touched

Whenever Gwenevere, Shadow Touched attacks,
it deals 3 damage divided as you choose among
up to three target creatures. Whenever a creature
dies this way, you get an experience counter.
{3}{u}{b}: Create, a legendary black Shade creature
token named Shadow Avatar. It has "This
creature's power and toughness are each equal to
the number of experience counters you have." Activate this ability only any time you can cast a sorcery.