Seriously tho your opponent must be a Lightning main and using Warrior's Killing Intent as the 1st passive which resets the cooldown of their mystery whenever the mystery kills a unit.
You must have had clones in your line-up, his mifune killed just any one of them clones with his mystery and combined with the Lightning Main's killing Intent. Auto reset Mystery.
Lmao You mean me? XD hahahaha I saw you writing in chat "mifune mystery 2 times in a row? How?" Dude, how about checking lightning main talents before you say "*UUUURRR".