So.. I have a dex of 5 n I can stand anywhere on the ground travel map (even on the exact same space as them) n no matter what I miss EVERY SINGLE SHOT n then get my ass kicked! Do they just have a really high dodge or something or am I experiencing some kind of bug?
"A guest is a fine shell washed up on the shore; welcome others as you were welcomed yourself, on gentle sands." – Nautolan folk proverb
Okay, so Katarn are Large and their Range is 0 - 2. source.
Every single shot missing is statistically unlikely (but possible). What is most likely, however, is you have either No weapon equipped, or a weapon whose min range is greater than whatever range you're at.
Check the weapon you/your squad have equipped, and the min/max range. Make sure you attack the Katarn from within that range. If that range is greater than 2 (the max range of the Katarn), all the better, because then IT will miss every single shot against you when it counter-attacks.
Else, provide more information about your setup so we can diagnose the issue.