[Tournaments-HotA] Mirrors-2

Started a new game, and again, the opponent, as if nothing happened, fielded this type of hero with a specialization in dragons. I understand that these heroes can be used?

Let's start with the fact that the opponent leaves the game without warning, refusing to finish the game until Vic says something (hopefully he saved).
Then, Mutare Drake, a regular hero with tactics and items, appeared on turn 111 in the tavern with a regular army. (Gives dragons +5 attack/defense). (Usually, the opponent gets a mirror image of Mutare, but I didn't ask for that). I wasn't planning on making him my main hero, so I don't understand what the problem is or why he's considered overpowered. After all, he's not a specialist in enchantments or snipers.