I like it too!

I have two comments:
- Dark Matter is a good ability, and I guess it is most likely to be used on the tank but it might pe problematic in its design if you want to use it on any party member that has higher Solution stacks but is out of range of enemies. Maybe make it work like <tt> macros: turn the solution stacks into an attack delivered to the target's target? Or have Dark Matter convert the current Solution stacks in Feedback, and then add a Feedback spender, directly targeting enemies in a small AoE?
Regardless, the idea of turning your party membrs into mines is cool!
- I think you would need to have a HUD element to have a better overview of available stacks of Solution to be used. Sometimes buff icons are messy to read within a fight, so either have some kind of count of how much is available, or a faint glow with 5 intensities on party members that the Medicus would be the only one to see.

Great work anyway