To put it simply, players will have to fight a BBEG that is way too powerful even for a full 6 player party of oddly made level 5 pregens...
Starting out the adventure was alright with the investigations that players had to carry out and clues that would easily be picked up eventually.
1st few encounters also just about right in terms of difficulty but still posed a threat that should be taken seriously.
Unfortunately, the last encounter with the BBEG was exetremely HORRIFYING. With over 100hp, 25+ AC, high SR, high DR, (VERY) high DCs for spells casted and instant teleport for hit and run tactics all in a tight room area... and that's not counting the fact that the BBEG's skills are insanely high, how do players survive with 6 poorly made level 5 pregens is beyond me. Oh and BBEG can just easily chase after any players that try to escape if the GM wants to be mercliess. BBEG is just a mere CR8? LIES! It's easily a CR10+ party killer encounter chucked in as a nasty final surprise.
Really, I almost felt like I wasted my time fighting against something that is impossible to kill without VERY good luck or an optimised veteran party...