nightelf37: Next entry!
The Story Crew Plays selector infected WIXOSS
This would cover only the selector seasons and not the lostorage ones, as I haven't watched the latter.
The story is seen through the POV of the Story Crew Field Operative Strelka, who was sent to the city specifically for a mission; locate the mastermind behind WIXOSS and put a stop to their nefarious plans. She gets acquainted with Ruko and her friends as part of the mission. She's also gotten other confidants prior to that.
Strelka is an aloof lady who often speaks in chess metaphors and can be a bit manipulative. Even if she isn't a Selector, she still duels against them, and has a little robot to stand in for her LRIG.
It would later be revealed that she doesn't see Ruko and company as friends at all, but as pawns in her game against the mastermind, with Ruko as the king and queen pieces simultaneously. While this puts a strain on relationships, it allows her to continue correspondence with Hitoe even after her third loss; because Strelka doesn't see her as a friend, the tainted wish doesn't affect her.
Eventually, just before the tournament at the construction site, while buying more cards, Strelka finds herself turned into a Selector when she acquires a Green living LRIG, who is given the name Karda, one Russian way for saying card. She now considers herself a bishop piece in this grand game.
Ever since then, Strelka seeks out Selectors and uses her LRIG's ability, which works like Piruluk's Peeping Analyze, to sense their opponent's wish. Before dueling, she also asks beforehand how many times they've already lost, while tracking her own losses. Depending on their answer, she might fold the fight in order to give them further chances to survive the system until she can stop it, or take them down with extreme prejudice.
As the investigation into the mastermind of the WIXOSS games progresses, Strelka's confidants start to dwindle as more and more of them lose thrice or become Eternal Girls, and she eventually is left with the main characters.
She joins Ruko to the special dimension where Mayu resides and takes her on first in a duel, allowing Ruko access to intel on Mayu's play style. Strelka loses, but it's thankfully not a third consecutive loss.
Upon the resolution of the conflict, with her mission over, Strelka leaves letters of farewell to Ruko, Yuzuki, and Hitoe. It ends with her at the train station personally saying goodbye to Karda, or specifically the human girl she originally was.
If I wanted to continue to lostorage, I probably wouldn't bring back Strelka, but have someone else be the SCFO investigating that game. The whole memory deal feels like a whole other twisted system from Mayu's.
Aaand that's it. See ya on Third! Elsewhere.