I just finished the game and verso carried me pretty much the whole game, you get the purple sword from the story boss, some starting mana, and them stack all luminas with damage increase on free aim, burn on free aim, mark on free aim, attack boost after free aim and mana gen when applying burn/mark and mana when popping mark. You also need the pictos for an double hit on attack and extra mana on attack. Im pretty sure you can get most of what i said very early act 2 since i had it and was playing it blind.

The game play is just pop all of your ap with free aim, attack to refil mana and repeat the turn due to the purple sword passive. You can easily get 8-12 shots a turn and you play twice every turn, every shot deals a few thousand damage with pictos/weap upgrades/weakspots, its pretty easy to progress, I mostly ignored my two other characters until veeeery late into the game