Im guessing you want official archer skill info? which I personally have no clue...
However if you are just looking for ideas of how it could work here's a couple.
Lay a trap on the ground - enemy walks over triggering it - turns them to stone (paralyse)
Lay a trap on the ground - enemy walks over triggering it - Stalagmite bursts from ground doing damage (could be big stalagmite for AoE damage)
Lay a trap on the ground - enemy walks over triggering it - Rocks fall from above either singular or multiple for AoE damage (but only in maps considered interiors (needs a ceiling to be cast)
I know you could come up with much better ideas for how you could make it work IceMan but I need the 3 forums posts so i can message in the Discord server so thought might as well put these ideas out there.