The previous reviews of this card have held up pretty well, but I wanted to add a few thoughts after months of playing with Sword Cane. It deserves the attention. I think we can now say that this unassuming little card has proven itself as a Mystic staple.
You can tell the designers had Dexter Drake in mind thematically and mechanically with this design. Sword Cane is indeed particularly good for him, but I think this card is excellent in vast majority of Mystic decks.
The most time-honored and traditionally effective way to play a Mystic is to stack a ton of Willpower boosts and try to use Willpower to do basically everything. As it turns out, Sword Cane just fits perfectly into that strategy. It lets you replace not one but two stats with Willpower, on a permanent basis, for a very low cost. That's so good!
Sword Cane's most powerful feature is that it lets you evade with Willpower. Its effect here is very comparable to Mists of R'lyeh. There are some differences--Sword Cane exhausts (but not on its enters-play trigger!), doesn't use charges, doesn't have the minor added bonus and penalty, etc. Basically, though, the cards accomplish the same task. Yet the biggest difference by far is that Sword Cane doesn't take up a hotly contested Arcane slot. Previously, running an evade spell on a Mystic meant either sacrificing an investigation or fight spell (an enormous price to pay) or running some clunky do-nothing asset like Sign Magick. Sword Cane totally gets around this. Hand slots are not at a premium for low-level Mystics. (Sure, you might want your Taboo'd Scroll of Secrets, but it's no problem to run that alongside Sword Cane.)
Sword Cane's Fight ability is much less powerful since a basic Fight action is much worse than a basic Evade action. The exhaustion clause is also much more relevant here--most enemies need to be evaded just once, but will take more than one hit to be killed. So, this won't adequately replace a combat spell. But that's fine, because you have your Arcane slots for that. And Sword Cane's ability is still really useful. It will save you charges on your main combat spell by taking out weak enemies like Swarm of Rats and Acolytes, or dealing that last point of damage to odd-health enemies. This is why some people like to run Wither as a supplement to Shrivelling. I always hated doing that, myself, because of the Arcane Slot issues and because Wither is so weak on its own. Sword Cane gives you all the benefits of this without any of the problems. It's a really nice effect to get stapled onto what was already a playable card.
Remember that it's usually better not to play Sword Cane prophylactically. This is because you get a free activation that doesn't exhaust Sword Cane when you first play it, so better to wait until you actually want to use it. Plus, if you end up never needing it, you won't have wasted the resources. There are exceptions, of course: maybe you want to protect your other assets from the encounter deck, or maybe you're Patrice and don't really have a choice.
To sum up, I'd say that if evasion is central to your strategy (maybe you're playing TFA or something), then you may still want to look at higher-level evade spells like Mists of R'lyeh IV for that big bonus to the evade check. But if you're a more typical Mystic that likes having the flexibility to evade, but only every once in a while, I think Sword Cane is substantially better than the various evasion spells and events. You're paying less and getting more.
I'll be honest, from a thematic perspective it feels a little silly that all my Mystics nowadays are venturing out to fight cosmic horror with Sword Canes in tow. But what can I say? This card just gets the job done.