Good to hear from you, Stratovarius

If you're willing to go the lengths to set up your own server (or play on Linux) then NWNX provides you with a way to count the race and class bonuses from illithid and lich as base stats rather than stat buffs. I am not an expert so cannot give you a detailed walkthrough on how to do that though.

Other than that I thought that if you create a character using NWN CC then your race stat bonuses are included as base stats in game? Though I cannot be sure

Which level are you? There are a couple things you might try.

Spamming summons is one of them - plague of undead is kinda powerful, the dead walk might provide unlimited meat.
As for SR, it is a pain in the ass especially if you lost warlock levels. Abandoning hellfire warlock, however, won't help with that - hellfire warlock advances invoker level as it should. delaying hellfire warlock until higher levels would only gain you 1 BAB. Abandoning shifter would also gain 1 BAB, but lose you the dex you get from the shape.

You could also try getting scrolls of mantle of egregious might, greater heroism, create magic tattoo for +12 AB in total. Other spells that come to mind are divine power, righteous might, battletide, prayer, blessing, divine favor...

Hellfire shield delivers eldritch blast damage and requires a reflex save, so it would hit, no idea about the SR though.

As far as Wall of Perilous Flame goes, it is bugged in that it deals (2d6+1)*Invoker Level damage instead of 2d6 +1*Invoker level. It still shouldn't penetrate SR automatically, but since you can stack that there's a high chance it will hit eventually. Then you can just Flee the Scene to the other side of the flames.

Lost Boy - eldritch chain on a lackey won't work as every creature struck requires a separate touch attack.

Overall practiced invoker is your friend, Since you need to be level 9 to get hellfire warlock and you were hfw 3, I guess you were level 12. With practiced invoker you would get one greater invocation leaving you with 3 least, 1 lesser, 1 greater. If you chose to pick warlock at level 9 you could get another least invocation through extra invocation. You could also get weapon focus ray for another +1 to attack - no idea if that would help though as I don't know the AC of the blue dragon - is it an adult blue dragon? If yes, his AC should be 28 - no idea about the touch AC though.

What to do with those: I like the trick with darkness+devil's sight, but I think dragons true seeing nullifies that. Summon swarm? Probably will not punch through DR. Beguiling influence helps avoid fights, while dark one's own luck helps with what Lost Boy said. Lesser invocations have chain, baneblast adds damage, but doesnt help punch through SR or hit, so pass. And you can't hit him with eldritch chain anyway... I dont think anything here helps you that much except flee the scene for running and ignore the pyre for elemental damage resistance. Oh, and the dead walk to make a meat shield.

Greater invocations is where its at: wall of perilous flame won't punch through SR but thanks to a bug deals immense damage. Stackable. Eldritch cone and line let you target reflex save with your EB, but won't punch through SR. Vitriolic blast is amazing, but you have to hit the touch attack. I believe the best option is to get chilling tentacles and stack the hell out of them. They ignore SR, deal bludgeon damage, on failed save root the dragon in place (won't happen often - but you STACK the tentacles) and deal 2d6 cold each round - I don't think there's a save on this. Just spam it and run in circles. Flee the scene and ignore the pyre should work just fine for that.

TL;DR
Get chilling tentacles, with practiced invoker you can get one greater invocation at level 12 and it should  be this one.

Also send me a save and your char and let me try.

Except for all monks, rogues, shadowdancers, ninjas, swordsages etc.

So you are leveling as pure warlock until epic levels and only then entering pnp shifter?

The problem with ecto shambler is they have to stay inside the area. No player will, and monsters will run out to hit you - if you enter, you also get hit if you play on the harder difficulty levels. Shadow body, etherealness, cloud mind wont really help with that...

Energy current is indeed great. I use it all the time.

Yeah, well, I play a psion... Actually being able to apply multiple metapsionics is an advantage over magic classes, as in nwn they can only ever add one. I think epic psionic focus is actually a fair feat. Though pre-epic psionic focus kinda sucks.

Does psionic meditation actually allow you to focus and manifest in one round? Because  in pnp if you focus as a move action you still have a standard action to manifest.

No problem, I am similarly inexperienced Just recently downloaded the svn repository of PRC and was about to start learning how to compile scripts and the entire PRC - I have some include changes prepared and I want to touch a couple scripts that are currently not functional or broken (for example Epic Eldritch Blast seems to require 20 levels of warlock instead of 9d6 Eldritch Blast, so is unavailable for Eldritch Disciple and Eldritch Theurge, even if total invoker level is equal to 20. Would have to change it to invoker level check, but then if someone in the future adds the Enlightened Spirit, we have another problem as it increases EB damage but does not increase invoker level Other examples include spells like Ring of Blades, Arrow of Bone or psionic power Bolt), it even makes some classes really hard to use - swordsage's maneuver recovery right now doesn't work at all, with conversation appearing, but not recovering maneuvers you chose (not that their mechanism was any good in the first place, but they have to be able to recover maneuvers somehow... Adaptive style would be good here to implement a full-round action recover all maneuvers).

If anything, I will be happy to learn from your mistakes and capitalize on what you learnt. And sorry for offtopic.