I noticed there aren't many places to find epic level build ideas for the updated incarnations of the PRC. I love building epic characters in NWN and I keep my designs in a spreadsheet so I figured I would share them here for anyone else who wants ideas. Here is my first one. I also believe this is the best high-level NWN build I have ever played.
What this build gives you: full warlock invoking by level 25, 16 pre-epic BAB for 4 attacks/round; charisma bonus to saves and an additional charisma bonus to one save of your choice; access to shifter forms starting at mid-to-high levels for massive AC, physical stats, and immunities; the ability to infinitely heal yourself (undead shape and utterdark eltritch doom); doubled eldritch blasts (eldritch sculptor, quadrupled with haste); doubled eldritch essences (lord of all essences); damage, attack and save bonus that stacks with each kill (lolth's meat); devastating critical with either falchion or scimitar (your choice, falchion is best but is not in the vanilla game); good scaling spell resistance; and CHILLING TENTACLES!
Weak points: invocations only have a caster level of 25; invocation save DCs are not super high; slows down a bit killing constructs, undead, and other critical-immune monsters. It may be worth working in extra invocation somewhere to get vitriolic blast to deal with spell resistance and the critical-immune stuff, but lolth's meat generally boosts the damage enough for me. You could also replace Flee the Scene after level 11 with vitriolic blast, but I would read the notes at the end before doing that - it will essentially force you to primarily use smaller Shifter forms until level 35.
Build Name: Rake (Malazan fans will get the name)
Race: Drow
Alignment: Any evil
STR 18
DEX 10
CON 10
WIS 13
INT 10
CHA 15
Lvl Class
1 Warlock 1: Power Attack, Eldritch Blast, Sickening Blast, Hide 2
2 WL 2: Eldritch Spear
3 WL 3: Cleave, DR 1/Cold Iron, Hide 3
4 WL 4: Deceive Item, Dark One's Own Luck, 19 STR
5 WL 5: Hide 4
6 WL 6: Lolth's Meat, Eldritch Chain
7 WL 7: DR 2/Cold Iron, Hide 5
8 WL 8: Fiendish Resilience 1, Beshadowed Blast, 20 STR
9 WL 9: Great Cleave
10 WL 10: Elemental Resistance 5, Flee the Scene
11 WL 11: DR 3/Cold Iron, Chilling Tentacles
12 Blackguard 1: Improved Critical (Falchion/Scimitar), Use Poison, 21 STR
13 BG 2: Smite Good, Dark Blessing
14 WL 12: Imbue Item
15 WL 13: Alertness, Fiendish Resilience 2, Noxious Blast
16 WL 14: 22 STR
17 BG 3: Turn Undead, Create Undead
18 BG 4: Sneak Attack +1d6
19 WL 15: DR 4/Cold Iron, Eldritch Cone
20 WL 16: Eldritch Doom, 23 STR
21 WL 17: Eldritch Sculptor
22 WL 18: Fiendish Resilience 5, Utterdark Blast
23 BG 5: Summon Fiend
24 WL 19: Lord of all Essences, DR 4/Cold Iron, 24 STR
25 WL 20: Elemental Reistance 10, Mask of Flesh
26 Shifter (PnP) 1: Greater Wild Shape, Creature Weapon Proficiency
27 Shifter 2: Overwhelming Critical (Falchion/Scimitar), Animal/Monstrous Humanoid Shape
28 Shifter 3: Large/Tiny/Beast Shape, Greater Wildshape 3/day, 25 STR
29 Shifter 4: Giant/Vermin Shape
30 Shifter 5: Devastating Critical (Falchion/Scimitar), Magical Beast Shape, Greater Wildshape 5/day
31 Shifter 6: Abberation/Ooze Shape
32 Shifter 7: Huge/Dragon Shape, Greater Wildshape 7/day, 16 CHA
33 Shifter 8: Daylight Adaptation, Undead/Construct Shape
34 Shifter 9: Elemental/Outsider Shape, Greater Wildshape 9/day
35 Shifter 10: Evershifting Form
36 WL 21: Epic Eldritch Blast, 17 CHA
37 WL 22
38 WL 23: B: Epic Eldritch Blast, DR 5/Cold Iron, Fiendish Resilience 7
39 WL 24: Epic Eldritch Blast
40 WL 25: 18 CHA
Some shape suggestions for Shifter if you can find them:
27: Asabi Chieftan, Dire Tiger
28: Brown Bear Companion, Bulette
29: Hill/Mountain Giant
30: Androsphinx
31: Battle Devourer
32: Old Red Dragon, Fire Giant
33: Demilich
34: Ancient Red Dragon
37: Dracolich (Best all-around form IMHO)
38: Mithral Golem
40: Prismatic Dragon, Adamantine Golem
Note, this is a great candidate for an undead template like necropolitan for the infinite utterdark eldritch doom healing mentioned above. Make sure to buy off the drow level adjustment with XP as soon as you can (level 6 and 9).
Note on Flee the Scene: this invocation allows the warlock to teleport a short distance. This invocation is great for convenience and kiting, but has a special use in this build. One issue with shifter is that many of the best forms are too large to fit through doors and before Shifter 10 this means you usually have to end your Greater Wildshape whenever you encounter a door. Flee the Scene allows you to walk up to a door and teleport through, thereby stretching out your daily uses of Greater Wildshape. Long, narrow passages and bridges will be the only things that will make you return to your normal shape.