in pnp or nwn2
in pnp:
warlock 10/enlightened spirit 10
you get
aura of courage, aura of meance,spirit blast,eldritch blast,spirit armor, celestial flight, tongues,shape invocation,energy resistance,holy blast,transform magic and death ward.
you also get the 10 lvl warlock capabilities
warlock 5/arcane caster 5/ eldritch theurge 10 or warlock 7/arcanecaster 3/ET 10
you get +1 invocation class lvl, +1 arcanecaster lvl, cold iron resistance, fiendish resiliance, spellblast,eldritch spellweave, great reachblast. you also get abilities of a 5 lvl arcane caster anda 5 lvl warlock or howevermany lvls you take in them. screw someone over, take 3 lvls of warlock and 8 lvls of warmage, just makesure you take battlecaster feat and 10 lvls of E. theurge.( well atleast i think it was 8 lvls of warmage for medium, might have been 4 for lightarmor which btw from my understanding you only need to take BC once )
warlock 7/ cleric 3/ eldritch disciple 10 or cleric 5/warlock 5. ED 10
what you get: gift of divine patron,turn/rebuke undead, 10 lvls of invocation class lvls, 9 lvls of divine caster lvls, eldritch spellweave, and timelessbody. you get multiple lvls of gift of divine patron, and it requires the character to be able to deal with undead, no druid for you or favored soul. or the other 2 baseclasses.
you also get the perks of the lvls of cleric and warlock you take.
more known builds in pnp:
warlock 10/acolyte of the skin 10
if you have complete arcane you can tell yourself this one.
in nwn2 and pnp: warlock 20