While it is true that Templar abilities do utilize the sole power (in a sense) of light manipulation to cancel out spells and deal damage, they are a bit more complex than that. The Templar ability tree can include healing, combat, and buffs. We would not allow a blank brush "Templar-esque" ability on an application for a character in Acatalepsy and would require it to be nerfed considerably in order to be considered. This was our mentality with a "new magical ability" for Group C -- swapping out Power A for Power B.

As a result, Morrigan would need to select one power to be swapped out with her current selection, rather than a branch of abilities. If she would like to use light manipulation, or utilizing light as an attack, that is fine, but it cannot be as broad/powerful as a Templar spell set. Alternatively, if you would rather have Morrigan be in Group A, that is fine! We have no issue with switching groups if that works better for you and what you had planned for the event.