Instead of keeping the third animation to be the same as the original spell animation, how about changing the second 'Reflect' animation to be similar to a "Spike" animation, with the ending result of the animation being your typical "en" proc.In the whole flow of the spell taking action: spell activates → reflect animation is displayed → reflected spell animation is displayed on yourself, this final part is impossible to do, and the best we can do is cut this animation and only display it in the log. Additionally, the animation needs to be in the memory, but there is a pending concern that the size would be pretty rough.
For example, this would be the series of Animations of a foe casting a spell on a player.
As far as other balance issues, bypass them. Keep the formula simple - Reflects a single target, hostile spell. No need to worry about casting curing magic and have it reflected on some random enemy, keep it one to one and balance it around that.
Enemy finishes casting animation - > Player "Reflect" Animations procs - > Enemy receives "Enlight" Damage animation to represent the reflected spell. (Or a similar effect.)
That should be able to bypass the current problem with the way the Animation memory works, and you'd only have to keep one static 'reflected' animation in memory.