Siona, Captain of the Pyleas is a uncommon Legendary Creature — Human Soldier card from Theros Beyond Death (THB), collector number 226. Current market price: $0.19 (foil $0.37), TCGplayer market prices via Scryfall.
When Siona enters, look at the top seven cards of your library. You may reveal an Aura card from among them and put it into your hand. Put the rest on the bottom of your library in a random order. Whenever an Aura you control becomes attached to a creature you control, create a 1/1 white Human Soldier creature token.