Windows/Steam version:
This week, the journey event troop Sir Ailuin receives x2 magic within the event. If the enemy team has the event troop, it also receives this bonus.
While not as obviously a bug as the shiny mirroring (although possibly related), I can’t imagine, this is intentional.
This event troop used infinity loop and solo destroyed my team 
On the other hand, when luck is on my side, it is the destruction of the enemy team. Luck on the enemy’s side is less common
The one I just met luckily was put into an elf team, not a knight team, so it did no harm.
Still those tend to be the most dangerous encounters ever since this type of journey troops was introduced with Chalcedony. I don’t know, if development creates these teams intentionally and knowingly.
The same thing happened to me in 1 battle. Up until that point, I didn’t even realize Ailuin showed up. It was too late by the time I realized, as he was already looping.
That exact situation happened to me, wasn’t paying attention and didn’t even realize the sucker was on the enemy team…