He's got plenty of experience with dodging enemy archers - and while those pistols of hers fire far more quickly than any bow or crossbow, he figures the same principles apply. So he runs, weaving this way and that. He has no illusions he can outrun all her bullets, but so long as he has enough magicka to keep up Oakflesh he can take a few hits.

He sees those discs, and while he doesn't know what exactly they do, it isn't hard to guess it's something he'll want to avoid. So he dives away from them, and conjures up another version of the wolf from before, which appears to be made of flames. It runs toward the boulder, stopping a short distance away, and promptly explodes.

It's not a big enough explosion for Natasha to get caught in the actual blast, but she'll certainly feel the heatwave, and it might distract her long enough to let Vanyel pull off his next trick - a literal disappearing act.