Not a GW hater, but not a big fan either (because of how the rewards sucks, not how war is made) here.
As it was already pointed out many times, your team doesn't counter his, in fact, it's actually begging to be destroyed by Mab & cie, here's why :
- High mana costs without mana burn immunity
- Primary mana generation source : exploders (wich may leave 4-matchs+)
- First source of damage : converting to skulls, with a frontlining troop that is not immune to frozen.
With that being said, there do seem to be something extremely wrong here : look at the very first cast from justice. Nothing strikes you?
Every single gem spawned, from either red or blue, spawns close to gems of the same color. Actually, a single one of the 10 gems created were not matched after the spell (because it was close to both blue gems and red gems.
Checking second cast : exact same thing happening with Green / Blue. Only one green gem wasn't spawned as a direct neighbour of one of the initial green gems (counting diagonals as neighbors), but still, only 2 gems away when there were as few as 8 green gems before the cast, and these were not much scattered around the board.
Third and last cast from Justice kinda confirms that, but then again, she picked blue / brown when there were over 13 gems of each color before the cast, scatterred all around the board, so this one isn't prroving anything.
I don't know if this is only a console thing, nor if this is just bad luck (it happened to me once on PC, but that's one in a thousand battles), but it does seem worth investigating in my opinion.
Fun point : Looking at the video, I noticed the AI isn't making the same decisions on PS4 / Xbox. At some point, Mab casted her spell instead of taking a 4 skull match. Such a match is very high in PC's AI order of priority. In fact, console AI seems smarter from here.