You're kinda making me crave some Evil Barry and Evil Len smut ;-)
You don’t know what you’ve done to me, anon, because my brain is all on Savitar!Barry right now. And while we don’t know all his details yet...
Imagine he’s from the VERY distant future, like...hundreds of years, because The Speed Force has allowed him to live that long, and the faster he got, the easier it was to manipulate his age until he was effectively immortal. We know he travels to distant times and dimensions like stepping through doorways, but still, that’s got to get boring and lonely after a while.
He wants company, a real consort, and since he’s long since left his love for Iris behind him, he searches his memory for anyone that could be his partner NOW, this version of him, who revels in power.
Who else but Leonard Snart?
Since he can go anywhere at any time, he looks through realities but is always disappointed. He wants HIS Snart.
Then he sees the Doomworld. Now THAT version of Snart seems fun, so desperate to live after learning of his inevitable demise that he pushes that much further into his villainy instead of falling to the pathetic weakness of heroism. THAT is the Snart that Barry wants.
So when Mick Rory is in the process of bringing Snart back to the past, Barry grabs him and creates a time remnant - keeping the timeline intact as if nothing out of the ordinary happened, while acquiring his own Snart to bring with him into the Speed Force.
“Who the hell are you?”
“I believe you remember me as The Flash.”
I remember a red suit.”
Barry steps out of his Savitar armor. “I upgraded a long time ago.”
This is the Snart before he saw Barry’s face. Even with the scars, Snart doesn’t seem disappointed. “And what do you want with me, Flash?”
“Savitar, god of speed.”
“Okay...”
“Would you like to be a god...Cold? Would you like immortality, to go everywhere and anywhere your heart desires?”
Snart was so sure he’d been about to go bust with Mick reeling him in like a jailer, and now here’s the most interesting offer yet - from a pretty face with something wicked in his eyes. “I’m listening.”
(I will definitely return to this to add actual smut, but if anyone wants to play in this world...)