Unless it was hugely buffed, it was fairly lackluster and is in desperate need of tweaking.

-It requires being in combat (so no cool trick with binding and staring into their eyes)
-It can only have one effect.
-It seemed to fail a whole lot even in the 90s with a high int thief
-Arcane vision seemed to do nothing to it (should do something cool)
-Almost all of these you need to basically be in combat to see effectiveness, which thieves in general don't want to do... especially a thief that can't read scrolls in combat (another missing ability for these thieves)
-Duration in rounds of combat makes this one of the shortest abilities in the game...
-No cool echoes

Now with it spelled out above it may seem cool, but it was very low on effectiveness across the board. For example, having someone have a "chance for attacks to fail" was like getting a single or maybe if you're lucky two feints across a couple rounds... maybe. Having the final ability of a very "meh" line of skills in general (I remember the original immortals saying they didn't think it was a real thief path) and after investing 34 points on things that could be so much more useful.... maybe if you could stack these (and it's even a 2 round lag to do this) it'd have worth but right now I'm not seeing it. It's supposed to be the light at the end of a very dim tunnel and you get to it thinking "I just made a guy for this?"

Maybe in a raid situation, you have a minimal chance of causing one guy to pincer another? Is that worth 34 points (or at least 12 points above lore of the ages)?

I'm still waiting for some thief to prove me wrong but you could spend your points almost every other path and get more mileage. Only things really worth having in that path are arcane lore, scrolls, and lore of the ages.