The Horizon Walker was always, for me, such an evocative prestige class in 3.5. I loved the idea of terrain mastery, with a character eventually comfortable with inter planar travel.
The idea was better than the execution, though -- I wanted a character that could facilitate plane-hopping adventures. The level 7 Plane Shift spell does that (in one of its uses) -- an ability that typically comes for spellcasters at level 13.
What I'd like to see here, as the level 11 ability, would be replace Distant Strike with the ability to cast, 1/long rest, a Plane shift spell on willing creatures. (and so excluding the attack vs. unwilling creatures option), and not requiring the material component.