I'm not quite sure how to interpret the terrain bond spell in conjunction with the horizon walker's terrain dominance.
You call upon the spirits of nature to help you adapt to your environment. You treat the terrain you are in as your most favored terrain until this spell ends.
If you do not have the favored terrain class feature, you gain no benefit from this spell.
Say my most favored terrain is underground, and I'm in a desert. I have terrain dominance for underground. Does it:
a) allow me to treat desert as if I had terrain dominance in desert since I have dominance in my most favored terrain?
b) allow me to treat desert as though it was underground?
c) afford only ranger favored terrain bonuses to desert terrain for the duration of the spell.
If it's b), does that extend to creatures such that desert=underground means (native to desert)=(native to underground)? That would essentially mean that anyone trying to use the homefield advantage just gives you an even bigger homefield advantage.
Also, how on earth do you determine a creature's native terrain? This spell seems much less straightforward than instant enemy.
I too have the same question
The way it reads to me (and several others that come to the boards) is this:
a) Terrain bond would allow you to treat desert as underground.
b) Since desert is now treated as underground, you get all the benefits that go with it, this includes terrain mastery and terrain dominance. This includes treating creatures native to deserts as creatures native to underground, giving you your terrain dominance "favored enemy" bonuses to them.
You determine a creature's native terrain by the Ecology line in its stat block.
It's powerful, but it's not game breaking. For one terrain bond is a 4th level spell, not easy to spam and a wand of one is not cheap. Second, you actually have to BE on the creature's native terrain if you want this combo to work. That can be more detrimental than positive (think Abyss, Plane of Fire, etc).