First of all, Duel is free, but it is not completely free and is partially paid, so if you want to purchase a card or use other services, you have to enter a booster pass code to get a kind of preferential ticket called Duelist Premium
That said, dealing 7 damage a turn to a player or permanent is a win condition or a removal spell each turn, so its definitely worth playing
If heads, prevent all damage done to this Pokemon by attacks during your opponent's next turn
You flip this card over, and your reward is a recreation of the iconic fight
2022-02-18 Phasing out doesn't cause permanents to leave or re-enter the battlefield, so no leaves the battlefield or enters the battlefield abilities will trigger, and Kaito's first ability won't trigger again at the end of a turn in which he phased in.
But the multiverse isnt infinite and not everything and anything exists within it