This Team uses all 6 colours. Lance Knight can be an effective Tank early in the game with Sacred Guardian as a back-up Tank and damage dealer. Alchemist is a Yellow Mana generator to provide Sacred Guardian with a lot of Spell casts and Boar Rider is good for setting up combos and gives you Extra Turns. Also, until the Update in early April, if you get an Extra Turn using Boar Rider’s Spell, you get 2 Extra Turns instead of one.
I know you don’t have the cards yet but I was going to let you know of a team I use that works out.
Treant
Alchemist
Valkyrie
Banshee
I like this team because once you get the traits on Valk you start to get tons of souls (which is always needed). You can use your hero instead of the Treant to begin with but if you’re able to eventually level and get the traits on the Treant he is a great tank/dmg dealer.
The strategy is pretty straight forward. Use Alch to create yellow gems to fill the Valk/Banshee mana and then use the Valk to get more blue gems so the Banshee ability does more dmg. If you wait for the right time to use abilities you can chain them together and never lose a turn. Usually by about turn 7-10 I can keep going with 4 and 5 gem matches never letting my opponent have a turn. Lots of wins and lots of souls.
I think Treant is a better fit, but War Sphinx can keep the board under your control and powers up cheaply. That said, just like Treant, War Sphinx is Ultra-Rare so you’ll have to be moderately lucky with some chests.
so teams that work now… may not be so hot later