Lorcana features a Shift mechanic which allows you to pay a reduced price to replace the card facing with another of the same character, which is a cost-effective way of swapping out versions mid-game
Manifold Mouse in particular enables valiant triggers and grants double strike to set up lethal Monstrous Rage attacks
Terra Branford Urza, Lord High Artificers rebranding as Terra Brandford, the main character of Final Fantasy VI, is fitting
Vivi also combos with Quicksilver Elemental to create infinite mana and can even win the game if you have a way to cast infinite spells to ping down opponents
Its a good card, no doubt, but six mana to choose two abilities (two of which just make two 2/2s or put two +1/+1 counters on something) just feels bad
This means that you really need to pick the right moment to cast Festival of Embers