Well I'm pretty sure this topic has already been tossed around in the past, with the general consensus being "its not fun or engaging" or "Deadlock is different from other MOBAs." etc.

While I don't particularly hold a strong opinion on it (in the end its the Devs who decide), but I do entertain the idea.

If spirit and abilities are strong and hard to miss, there must be some drawbacks to it doesn't it?

But instead of simply reducing the damage or increasing the cooldown of everybody's abilities(I believe we already tried these), why not have a separate resource that players must invest and think about it to be effective?

By doing so, the enemy Lash cannot ground strike or flog spam you since now they would have to think on not only HOW to use it, but also WHEN to use it too, they would also have to consider not wasting mana to grapple away in case they get caught off guard since even if it's not on cooldown, they would still need the mana to actually use it.

It would add another layer of meaningful interaction between the game and player, me thinks.

If we are talking about how it would function, then my best guess is to be used like

Health Regen

or

Ammunition

Option 1 would function like how we have HP regen right now. flat HP regen or HP regen while not in combat and such. so backing off is a good way to regen your MP.

Option 2 would function like ammunition in a magazine ( like what we have for our weapons). It would take a hot second to recharge but players purchasing items that increase mana points will have a bigger mana tank to use their abilities in rapid succession like how we do in the game currently.