I'm gonna list some things:
-Midazolam cannot be farmed, only bought or found
-deals 1/4 normal xbow damage (is this on top of the 125%?)
-has an 12(!) turn CD
-takes up a utility slot
-some enemies are immune (crawlers for instance)
-obviously doesnt work on robots
-duration is lower against tougher/larger enemies
Garbage. I advocate for getting rid of the CD entirely. The only abuse I can think of is tranq'ing an enemy in a choke point so you can shoot the ones behind it, but in that case you can't use your best two bolts: fire and shock because they'll wake it up.
You could add a status similar to aphobia so you can't chain-tranq the same enemy over and over.
