From the borderless cards of Aetherdrift , this can be a rude rider rare (7.5%), revved up rare (6.4%), graffiti giants mythic rare (2.3%), revved up mythic rare (1.1%), or rude rider mythic rare (0.3%)
While Starmie ex does have less HP than many other ex cards in the format, it is a consistent early-game threat that can win the game before other decks get set up
Basically, you might want to end your turn whenever you dont want a bad trigger or spell to happen, or if youd be penalized by an effect at the end of your turn
It will likely take the games actual release to see how popular it will be with players, but there are some indications from other TCGs that this style of game may actually be a big win for Pokmon
You can use Lure cards for a similar effect
One of which is a fantastic Water Pokemon that can utilize Misty for a turn-one attack