The spell steel wind strike says that you
vanish to strike like the wind.
At first glance you might read this as an inconsequential part of the description. But strictly speaking there is no flavour text in spell descriptions. Vanishing implies being unseen, which (if we carry on the logic) grants advantage on attacks due to being unseen.
I’ve seen this argument appear in a couple of answers recently and thought it deserved a question of its own.
However, steel wind strike looks like a pretty strong spell without advantage, and granting advantage on all the attacks seems like something too important to leave to a bit of rules lawyering, which makes be doubt this interpretation.
Do you intrinsically gain advantage on all of steel wind strike‘s attacks?