Roh Vin, Leader of the Bazaar

When Roh Vin, Leader of the Bizarre enters the battlefield, create Niss, Guardian of the Bizarre,
a legendary 3/3 green Elf Warrior token, with the ability "Whenever you attack with three or more
elves, Niss, Guardian of the Bazaar can't be
blocked"
Whenever you attack with three or more elves,
Roh Vin, Leader of the Bazaar can't be blocked