What does 'move across' mean?

[Raoiley]

As in hexwraiths... Does it mean move across fully, ending move 3 inches away? Pretty rate in that case, assuming you start 3 away, finish 3 away and a unit is probably a few inches deep.

 

Or.. does it mean as long as you touch it? As in, move forward, across the front of their base and then move back outside of 3?

[CaptainSoup]

In my experience the ability and others like it entails as long as your model's base crosses over the opponent model's base, the ability activates. This means even if the long edge of your hexwraith base barely brushes the base of say, a khrone bloodthirster while moving, the ability can work on the bloodthirsters.