The wind looms are the same for Danyel as for Master Soulweaver. I'd love to see a reskin as an inn reward or some such in the future, but there's something of a shortage of artists already.
I thought perhaps Master Soulweaver's artifact should increase its defensive capabilities. It can already outstrip BSW in terms of damage; and in the case of MSW, the bonus damage from Soulsynch is actually about equal to using Soulsynch in the rotation, and all its defensive abilities are also offensive ones.
When I tried it against Yllmar, and it provided such impenetrable defenses that I never even needed to worry about the guests dying (which is the grand flaw in the BSW strategy I used). That said, MSW's stun has a much longer cooldown, so it's much slower, since Yllmar can heal more often, and timewise BSW was still better.
Even before Yllmar, I thought perhaps an artifact should increase the probability of stunning on Vacuum to 100%-- it's already possible to stun every time you use it given some luck (since even in a bossfight you'll likely use it a maximum of five times), and chance isn't great for planning. Dual stun classes aren't exactly unheard of.
In a similar vein, applying Concentration's effect to health as well as mana would be very significant.
Moving on to more convoluted ideas, perhaps longer effect times and longer cooldowns, to make up for stronger retribution or soulsynch skills-- giving Seal's debuff an effect lasting 7-10 turns, and cooldown of 15 (since it's a 200% damage skill, you lose 100% over the time it takes for regular Master Soulweaver to use it twice). Since the majority of MSW's damage comes from damage boosts to debuffing skills, you could easily account for something like added damage to Soulsynch. If the shield has even 1.5x duration and cooldown, that nerfs it since banish--soul aegis--seal--banish--vacuum provides such impenetrable defense. The extra shield time makes no difference, since banish has a cooldown the duration of the two-turn shield, while the added cooldown time outstrips the bonus turn from the shield.
MSW uses short cooldowns to its advantage, which I'm actually rather fond of, however it has no good mob clearing abilities, which makes it less fun to play.
It's not as though Master Soulweaver's baltaelsynch needs to be the full 1000%, either. 700% is enough for almost every mob, and it might be easier to balance. Especially if the damage is spread across soulsynch and retribution, with its longer cooldown (which would make most mobs a lot faster).
Alternately, a synchronized 'mode' might be cool, wherein activating Soulsynch engages the modified skills, or it works like SWoT's Umbral. However, unless the code can be somehow borrowed easily from SWoT, that's probably way overcomplicated. Certainly cosmetically, if we look like synchronized Tomix or use Soulblink as a run cycle, it'd be cool.