Long Trail is a legendary major card out of the New mechanic pool. Affinity Dash lays a 0.4 s trail (6.1 u) at 90% speed on a 40% longer cooldown.

You can take it once · it only turns up when your Dash 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 Blazing Trail and Quick Trail. Take one and the rest are gone for the run.