Seeing double (смешанная)

Prompt (story diverges from this)
Arthur is being tested.
A sorcerer makes a few dozen copies of Merlin.
Sorcerer: if you're really that good of a king, then you'll figure out who the real one is.
Arthur thinks it's easy. But all of these Merlin's seem to have a quirk of Merlin's intensified. It makes things difficult, because Merlin has days when he acts exactly like that.
Only one thing he knows for sure. It's definitely not the one who just defeated one of the other Merlin's with magic.
Excerpt:
Arthur reached for his sword, just in case. “What do you want me to do? Figure out which the real Merlin is?”
“Exactly.” The mercenary’s eyes glinted with mischief and he suddenly looked much more like a threat. “These Merlin’s have been designed, based on YOUR thoughts about him,”
Arthur immediately flushed