Blade Halo is a legendary major card out of the New mechanic pool. Fan of Knives throws one ring of 12 knives that circle you for 3 s, then fly 4.2 u.

You can take it once · it only turns up when your Special ability can actually use it · it can be offered for 0 of the 34 abilities.

Only one card can reshape that ability this way — this one, or Volley Storm and Piercing Fan. Take one and the rest are gone for the run.