That magic is way more customisable and adaptable than any other kind I think. Letting you for example use words like stop (letta) and a lift (reisa) which are verbs. Any kind of "other" magic is more limited. You can even have Necromancers using this magic, so basically if you want voodoo rite sort of things. You can make your Navren say a couple of words which he either does or doesnt know the meaning of. Maybe making the spirits come and kind of posess the heads, or making the heads straight up sing more words of the Ancient Language which then causes something to happen.

Honestly, with the Ancient Language you can do everything that you can do with other magic.
You just gotta figure out how you'd go about making it work