I have Ametrine. If I applied her skills on less then 300% she will go empty: f.e. 153%-> 0%. But may be it is better to apply only 100%s of % ?
In my suggestion: 153%->53% (and apply of 100%).
Another suggestion(may be not to Ametrin but ninja): when applyied maximum it can be +50% of maximum of mana, then +50, etc.
300%, applied->0, max= 350. Then 315%,applied->15%, max=400. Then you can apply 300% and then 100% sequentially when mana will be full…
P.s. sorry if I my language little bit like Yoda’s)))