This kind of feature though would be the perfect way to simulate the "batman" aspect the OP was going for.
We players are not batman, we could not ever be as prepared as he is. The way to mirror that though is with retroactive mechanics.
DM: A minotaur comes through the door!
Ranger: (using ability). My stink bomb trap is set off, and that malder berry is especially pungent to bulls.
DM: The minotaur backs away.
Other players: How did you know a minotaur was coming?
Ranger: Well based on the tracks I saw early, that particular smell in the air I noticed early, and ........
By letting players set the ability after the fact, but saying that the ability was "there the whole time", it lets players model that incredibly intelligent, well prepared archetype