This deck DOES have potential to work but there's a certain ratio that needs to be met as far as game play and certain color values you need to emphasis on. For example:
Trial of Solidarity (can give multiple creatures a temporary power boost AND
vigilance until the E.O.T.)
Trial of Knowledge (gives you card draw)
Trial of Ambition (makes the opponent sac a creature)
Trial of Zeal (deals Damage)
Trial of Strength (makes a creature)
All of these cards do something but depending on how you play this deck will dictate HOW you want to
balance it out. Also since you have multiple Cartouches in this deck then you should have multiple Trials in this deck. Really you should have, in my opinion, 2x-3x copies of both the
Trial of Zeal & the
Trial of Ambition. Simply because playing these cards multiple times WILL have a negative effect on your opponent. These are cards that you want to play multiple times a turn if you can. The other White, Blue, and Green
trial you can get away with the 1x-2x copies of each. Yes you do have a lot of creatures in this deck but having more of the red and black trials will help maintain the board state and
tear apart your opponent's field as you get your big threats out.
As a creature recommendation you may want to add
Nimble-Blade Khenra. It's a nice 1/2 for 2 mana and it has Prowess. That means while you are playing your cartouches and trials multiple times then you can get some insane prowess triggers AND some aggressive plays. Also
trueheart duelist,
unwavering initiate,
naga oracle,
cursed minotaur,
wasteland scorpion,
emberhorn minotaur,
Channeler initiate,
Ahn-Crop champion, and
weaver of currents would be admirable choices for this deck. They all have abilities that either push the agenda of the deck or would gain even more value once you start dropping cartouches. For spell recommendation
benefaction of Rhonas would be a good choice because it lets you choose the enchantment AND/or creature that you want to your hand. That's practically a 2 for 1 card play. What do you think of these choices?