How to give Karma an update

I love this champion to death but after the 5.10 patch she just has been forced into a support role and it just doesn't feel like the same.

To start off this update I have thought about giving her a stacking mechanic sort of similar to how Swain got in 9.14. It kind of make sense since her passive is called 'Gathering Fire' so I was like eh I will give it a shot and see what I can come with and I think I nailed it maybe(?) but I need feedback on it to make sure I nailed or if things can be altered.

(P) Gathering Fire: Reduces Mantra's cooldown each time Karma damages an enemy champion with one of her abilities (Half-effect for Karma's basic attacks)

Additionally, Karma gains a stack of Gathering Fire, Enhancing her Mantra's Effect at level 6. She can gain stacks by killing champions, or dealing damage with her abilities

At 50/100/150 stacks, Soul Flare's eruption burns enemy champions for 75/150/225(0.35% Ability Power) over 2 seconds. This burn does not reduce Mantra's Cooldown.

At 50/100/150 stacks, Renewal tethers additional enemies beyond her primary target. She tethers 0/1/2 additional enemies and deals bonus 30/60/90(0.1% Ability Power).

At 50/100/150 stacks, Defiance gains additional Shielding strength and deals damage around the primary target, dealing 30%/40%/50% of the shield's value.

I hope this gives insight on Karma being strong again but I am not sure if this will solve some problems of her being in the mid-lane while not making her a totally broken support.