Prism (Aligned Form Hints)
From LSWiki
Prism does exactly what it sounds like it does. It refracts things, more specifically damage. It's a very nice Form to have to Aligned who want to fight multiple things at once.
Among damage refraction, Prism does a whole bunch of other nice things to those you use it on, although the form is short, it is one of the more ... deadly ones.
The help file for Prism mentions that it is by far "the most destructive form for any Aligned".
The form only has 1 knowledge requirement, and that is to complete a quest.
The quest is directly related to Hanoma, and can be completed on Hanoma.
Seek out Taiji for more information.