Daenerys, Breaker of Chains

Banding
When Daenerys enters the battlefield, Daenerys
deals 5 damage to each player for each creature
they control but do not own. Then, each player
gains control of all creatures they own.
If a player would gain control of a creature they
do not own, instead they lose 5 life.
{r/w}{r/w}, {t}: Daenerys X deals damage to target attacking creature, where X is the number of creatures you control.