Nice video, keep them coming!

Personally, at first sight I was drawn more to Kaylia Silverleaf.
Very straightforward ability that can be extremely worth it in some specific mana ranges especially when you're able to use a few magic attackers.

Tied for second spot were Fithe Bladestone and Bella.
I think the fire one has a better effect to give, +2 armor to anyone and not just dwarves.
Bella can still be game changing in very specific rulesets like you showcased there!
Her and Reklah from Rebellion are interesting "soft counters" to Tofu and it's extremely satisfying to pull off those wins.

Razi Clanktrap is strong too and there's some powerful gnomes and death cards in general, I just personally haven't experimented too much with it yet.

The one I truly don't get is Gorgug for the water splinter and orc synergies, seems a bit too convoluted to work. I think perhaps it was a bit limited in its design because the incredibly strong Venka is an orc. If you can play Venka I imagine that summoner is more appealing.

I play at the novice, bronze and silver levels and that's been my experience anyway.