Alter Animator with script - Or better alternative.

I am trying to set up a character that can perform special moves which are equipped into slots. In game each slot is activated by a constant input (button1 activates whichever move is equipped to slot 1 no matter what), and the system needs to be scaleable so I can add moves as much as I want. Some of these animations have multiple mechanim nodes (as an example one move the character zooms forward and strikes with a sword. If the character reaches an enemy before the maximum length of the zoom they stop and strike early. This is accomplished with transitions based on time and triggers). So not all of my moves are merely single animation clips that play until they finish.

Now I imagine I could create a monstrous animator tree which contains all animations the character can do, and a unique trigger for each one that I can keep track of in a script, but I’d really like to know if there is a more elegant solution. Like if I could construct a system of transitions and nodes, save it separately, and then add or remove it from the character’s animator during run time. Or if there’s a simpler way to do it altogether.
Please let me know if I didn’t explain my use case well enough.

I feel like I was too vague so I want to explain by being very specific.

In my game players equip special abilities to one of 3 slots. These abilities might have complex animations which are different based on context and rely on conditional transitions and scripts. A special ability like “Super Slash” is not activated by a “super slash button” but by whichever button is assigned to the slot containing the “Super Slash”. There may be dozens of special abilities with no coherent commonality between them. An ability might trigger an animation which uses events to drive the behavior. The ability might merely play a single clip while scripts drive behavior in some other way. An ability could be purely a “movement” ability to move the character in some special way.
Is setting up all possible moves in an animator Controller (and all necessary unique triggers and variables) the only way to do this or is there an elegant solution that will allow me to build each ability separately and then add it to the player character’s animation controller? Or even better, is there some utility that lets me achieve these results in an easier way?

i know your pain, to be abandoned, even being so correct…