In case you have not noticed in the tournament threads - I finally took skyharbor602's advice and raised my Dark dragon to level 15 and he's been doing great against the Champion types. He's only 400 essence in the codex and does not take to much food to raise up.

So, here are my new go-to's

Diamond and Achilles at 15 - first go at level 17 and below hard champions (pure champion types, Amazon, Harmony Knight) and Diamond types
Dark 15 - new go to for high level pure champs (17-20 pure champions, Amazon, Harmony Knight)
Mithril and Croconile at 12 - go tos for other champions (Huntress, Mithril, Plunder, etc).
Creator 14 - go to for cosmic, pink, white
Dark Omen 14 - go to for blue, purple, yellow green
Glasswing 14 - general go to if I'm not sure. I generally do not use him for pink and cosmic but for some of the same colors as Dark Omen.
Aquarknight 13 - I use him similar to Glasswing but mostly for battling with Tropic type bingo square.
Jungle Warrior at 14 and Delver at 12 - first option if I'm trying to get a bingo square for winning with a stone type dragon

I raised Music to 12 for the bingo square but I do not use him as much in tournaments
Triceratops is my go to for Dino bingo square but he's only at 10 and I'm very cautious about fighting with him because it isn't great.

I will say I notice a big difference between level 10 and 12 with battling for the same dragon - they just seem to get exponentially better.

I do use my other level 12 to 14 dragons at times, these are just my standards that seem to do well when I'm in a hurry or not in a place where I can verify with the chart.

I still miss the videos, they would be nice to have but having that Dark dragon means in the last two tournaments I finished with two days to spare.