When people had told Merlin he was the most powerful warlock to ever live, he'd assumed they'd meant in Albion or, in his more arrogant moments, the world.
He'd never ever dreamed they meant the multiverse.
Because apparently Emrys was so special and so unique, there couldn't possibly be two of him much less hundreds. And apparently (though Merlin had known this from the start) Arthur without Merlin died really, really quickly, and being the Once and Future Prat that he was, that meant Merlin would just have to go from reality to reality to help him, now wouldn't it?
There'd been Angsty!Arthur, Warlord!Arthur, Illegitimate!Arthur, Abusive!Arthur, Overprotective!Arthur (that one had been kind of nice), Perceptive!Arthur (that one had been weird), Actually-in-touch-with-his-emotions!Arthur (that one had been even weirder), Poet!Arthur (don't even get him started on that one) . . . . The list went on and on. And since they all had that future bit tacked on to their titles, someday he'd get to run through the whole list again. Oh, joy.
A lot of things had been different from reality to reality both in Arthur's life and his death, but one thing always remained constant: Mordred always struck the blow. Always. Sometimes it was an accident, sometimes it was a well plotted revenge, sometimes it wasn't even the original Mordred, but it was always someone bearing the name, and it never got any easier to his dollophead die.
This time he thought he'd finally caught a break. Mordred had been a low level assassin. Clearly evil, so no one cared when Merlin killed him, not important enough to be a martyr and have evil villains of the family variety name their kids after them . . . . When the prophets started showing up saying that Arthur was to die at Mordred's hand, Merlin was feeling positively smug. Nope, Mordred's in a shallow grave somewhere in the forest. No prophecies needed here.
Too shallow of a grave as it turned out. It had been raining a lot recently. They'd been fighting bandits in the woods, and Arthur, well, Arthur had tripped over the newly exposed, skeletal hand and been skewered.
Destiny, Merlin decided, had a sick sense of humor.
. . . . .
Arthur was sick. For once, Merlin couldn't heal him.
"I don't understand why it's not working!"
Arthur coughed. It sounded like he was about to hack up a lung. Or possibly a kidney. "Don't worry about it. It's going around all the knights."
Merlin froze. "Who got it first?"
"What? Oh, I think Mordred brought it back with him from his trip to the south."
Merlin turned slowly to look at the wheezing Mordred. "Seriously? Seriously, Mordred?"
"It can't be a sword fight every time," he said defensively. "We'd get bored."
"Bored," Merlin said dangerously. "Bored."
After a very satisfying chase that ended with Mordred being turned into a toad, Merlin returned to his king only to discover he'd expired in the interim.
Merlin buried his face in his hands.
He gave up.
Not, of course, that that stopped him from going on to the next one. They'd see how much damage Mordred could cause as a toad.