In episode 57 and 58 she, Rekka and Kourin watched the fight between Ren and Kai in Foo Fighter HQ together with Aichi, after Ren defeated Kai he thanked Suiko for the Phantom Blaster Overlord card, though he stated he would have won even without it.
After that, she presented Aichi two cards and a choice; he could choose the card of darkness that blankets the light like Ren did, or the card of light that consumes the darkness but the episode ended just when Aichi was about to choose.
The more quiet sister of the three, Suiko is able to hide her intentions quite well. Like Rekka, she is quite straight forward, though she is less forceful and is shown to admire those who are able to see their mistakes and correcting them.
When it comes to cardfighting, she is quite skilled and is not to be underminded.