I'm not sure what class your main character was, but mine was a pathetic wizard who stupidly thought I might get away with picking more situational cantrips so when I went up against 3 intellect devourers with just a wizard on low ground and a trickery cleric it took me a couple of tries to get lucky and not have my shit pushed in, so I had the alternative situation in feeling like CR was skewed in such a way that it generally screwed me over, and when I got to the underdark the minotaurs and dwarves forced me to swap out gale who I liked more, because wizards were just not effective enough in combat to even begin to handle shit that really shoulda been higher than "level 4" according to CR
Drow ranger - one shot, one kill per round from a hidden position on the ledge... they didn't even reach Shadowheart, who was standing on the ground floor as bait. Still, they each took about 10-15 or so damage to take down and awarded 10XP. Hardly a CR7 creature.
Dont know where you are getting your info from but an intellect devourer is most defenitly NOT a CR7 challenge. A quick google search gave me this:
https://forgottenrealms.fandom.com/wiki/Intellect_devourerWhich shows a CR of 2. And the monster isent using its abilites. Which can be explained by the presence of the tadpols. Maybe they are just trying to disable us rather then kill us to prevent us from getting away.
From the official 5e SRD... but I could get my books real quick, if you prefer.
https://www.5esrd.com/gamemastering...type/aberrations/intellect-devourer-3pp/
