@dougrayman Perhaps these two are discovering new ways to use magic and aren't even realizing it yet. It could be the first step toward shortened or even completely skipped incantations.
@Varler Depends on the setting, but in most, incantations are effectively magical shorthand to guide your brain down the pathways necessary for a certain spell; in some settings, even the language used may be important, as it helps shield your brain from the magical energies, but the words themselves typically aren't. As long as Saitou's words are guiding his mind down the proper pathways, it probably doesn't actually matter if he's saying them or not while channeling the spell.