I've been rethinking about what would eventually make Tsukasa leave WxS in my kasa7 WRONG PATH AU, so here's what I came up with.
Tsukasa finishes Sakaki's training like normal, but when Sakaki offers to take him under his wing if he leaves wxs, Tsukasa refuses. Even though Tsukasa is more emotionally distant from them now, they're still his friends and he wants to continue performing with them.
I imagine that Nene still manages to snap him out of his trance during their performance, so Tsukasa is a bit more rational when confronted by Sakaki.
Sakaki doesn't plan on letting Tsukasa get away that easily however, so he comes up with a compromise. I imagine he would say something like this:
"Tsukasa, I understand you not wanting to leave your friends, but I still think you can become even greater. So how about this? You get to stay with them, but you will have special one-on-one practice with me every other day. That sounds like a fair compromise, doesn't it?"
Even though Sakaki's methods are brutal, it was thanks to them that Tsukasa was able to put on an unforgettable performance. And besides.. A little risk is necessary in order to improve, right?
So with all that in mind, Tsukasa agrees, and Sakaki gives him the schedule.
During this special training, Sakaki begins slowly planting the idea in Tsukasa's head that his friends are holding him back, because they don't want him to surpass them. But Tsukasa knows this isn't true, he knows that they celebrate his breakthroughs and want to see him improve. But as the special training continues wearing down his mental state, and with Rui's directing becoming less and less effective. Tsukasa eventually reaches his breaking point and snaps. He yells-
"Sakaki would never let my talents be wasted like this!!"
He storms off, and goes to his special practice with Sakaki. Leaving the rest of WxS shocked and concerned.
During practice, Sakaki notices Tsukasa acting differently. He's not talking as much and seems to have something on his mind..
Sakaki decides to go onto the next stage. It would play out the same as before, with Sakaki mentioning Tsukasa being less focused, and that he should try distancing himself from whatever or whoever it is that is making him distracted.
It's at this moment where all of the negative thoughts planted in his head comes to ahead, and Tsukasa finally breaks.. the light leaving his eyes for good.. his rational thinking is severely distorted, only being filled up with Sakaki's lies and deception..
(I thought they were my friends.. I thought they wanted to.. help me achieve my dreams... but.. were they really just holding me back this whole time...?)
(Did they not want me to succeed..? Did they just... want to trick me...?)
Sakaki places a hand on Tsukasa's shoulder and smirks. Tsukasa looks up with lifeless eyes, but Sakaki isn't concerned. He just smiles and responds in his usual casual tone.
"But.. I think you're mature enough to come to your own conclusion."
"My own... conclusion...?"
Sakaki nods and takes his hand off Tsukasa's shoulder.
"I think we should take a break from practice today."
Hearing this, Tsukasa's shoulders tense and he pleads with Sakaki that he doesn't need a break, that he can do better and-
But Sakaki cuts him off, and responds with an unusually stern tone, putting Tsukasa back in his place.
"With your mind wandering around, it would only be a waste of my time."
"My time is very valuable, you know?"
Tsukasa doesn't respond, his piercing gaze making him too stunned to speak.
"I have other things I could be doing, but I'm actively choosing to spend my time on you."
Tsukasa starts breathing heavily.
"You should be grateful that I'm giving you this opportunity."
Tsukasa's vision starts tunneling.
"So until you get it together, we are putting the practice on hold. Understood?"
Sakaki waits for a reply. Tsukasa, despite being shaken up and petrified, manages to choke out a quiet "u-understood.." under his breath.
And just like that, Sakaki goes back to his usual self. Like nothing even happened. Before he leaves, Sakaki reiterates that he believes Tsukasa will come to the correct conclusion.
Tsukasa is left silent, and his throat and chest felt tight.
Sakaki is able to push Tsukasa beyond expectations. Creating a performance that's indistinguishable from reality. That is something Rui never managed to do.
Sure, it's brutal, and painful, but it's what every great actor has to go through, in order to become a star. And if that's what it takes..
Then Tsukasa has no other choice.
-------------------------------
Tsukasa meets up with his troupe one last time, and before Rui can apologize for holding him back. Tsukasa responds with a hollow tone.
"Thanks for everything up until now.. but I've decided to go my own path.." Everyone is shocked.. Tsukasa is.. Leaving?
Rui is the first to object. "Tsukasa-kun, wait! I didn't mean to hold you back, I promise. If you give me some time I'm sure I can figure something out-"
"-Y-yeah! If we put our minds together, I'm absolutely positive that we'll figure it out!"
Nene joins in too, but quieter than the rest.
Tsukasa smiles weakly, their words going in one ear, and out the other. He enjoyed his time with them thoroughly, but it's time to stop playing pretend. He can't move forward with them anymore.
The only way forward.. is with Sakaki.
