Archer's True Identity.
Please don't ask which route this is, but Shirou, Saber, Rin, Archer, Shinji and Rider had just all pulled back from a violent three way battle at the park, each Servant silently flinching as they subtly nursed fresh, large wounds.
Well, Shirou, Saber, Rin, Archer and Rider were pulling back. Shinji had stood back the whole time. That had been mere strategic acumen and not cowardy, really, and he would prove so, by boldly standing behind Rider while pointing and saying, "Archer! Wait! Before this goes any further... listen to me!"
Shirou blinked. "Shinji? You still are here? I thought you had ran away!"
"I'm not talking to you, Emiya!" Shinji snapped.
"Well, actually--" Archer groaned, then shook his head. "Never mind. What do you want, then? Giving up already?"
"I have figured your identity out!" Shinji told him. "And that's why there's no reason for us to fight!"
"Oh, really?" Archer snorted, while Rin looked about to vomit all of a sudden, and Shirou, Rider and Saber only frowned in confusion.
Shinji smiled and nodded. "You are no famous, renowned hero in this era, that's for sure. Nothing about your attire or weapons, or even your fighting style, refers to any famous fighter from any particular legend. Yet you're obviously skilled, I'll give you that. And handsome."
Shirou blinked. "Shinji, are you trying to seduce Tohsaka's Servant?!"
"Well, I guess it's the best he could do by this point..." Rin snarked bitterly.
"I'm not!" Shinji stomped a foot down. "Archer, I've read on all there's available to learn about the Throne of Heroes. My family started the means to contact the damn place, after all! I know the leading theories are it's timeless, spanning past, present and future. That's why your legend isn't known to us; it hasn't been written yet! But it will, oh yes! You come from the future! And since Tohsaka is piss poor now and couldn't allow herself a catalyst, she must have summoned you through compatibility--"
"Spoken by the guy who lives in the Addams Family manor about to break down and covered in bugs!" Rin yelled at him. "When was the last time you could allow yourselves a decent exterminator?!"
Archer, meanwhile, was just scowling at this rambling idiot. Had he understimated him somehow?
Shinji kept on pointing at him, confidently. "And I've also learned use of several types of magic, mostly those allowing shortcuts to hardworking but otherwise... differently gifted types, may darken the sky and bleach the hair down! So, let's recap! Who is no doubt fated for a future of greatness, has a compatibility with Tohsaka, is a clever combat strategist, and is devastatingly good looking and cool?"
"Are you trying to tell us," a jaded Rin said, "Archer is me from the future?"
"Archer, you're clearly ME!" Shinji grinned. "You can drop the pretenses, Heroic Spirit MATOU! I know you have come here to witness my, nay, our triumph, and so now I welcome you as my ally, Handsome...!"
While Saber, Rin and Rider only blanched out in disgust, Archer blinked, clenched his teeth, looked as if brimming with untold white hot fury for several seconds, tightening the grip on his blades...
And then he began laughing hysterically, just at the same time as Shinji.
Shirou blinked, looking back and forth between them. "... wow. I suppose this explains why both of them hate me so much, then...!"