Hexwraiths and Hellwraiths can move through unengaged units (whether friendly or enemy) during the Remaining Moves sub-phase, but cannot end their movement within 1" of another unit.
Source: Warhammer Armies Project: Unofficial 9th Edition (v2.2)
Hexwraiths and Hellwraiths can move through unengaged units (whether friendly or enemy) during the Remaining Moves sub-phase, but cannot end their movement within 1" of another unit.