This thread:
http://boards1.wizards.com/showthread.php?s=&threadid=57321<br />
has details on how to make a rogue/cleric into an arcane trickster. rogue1/cleric4/darkmask5/ND1/trickster9
18th casting
needs magical training(FRCS) to cast mage hand
not bad, 18th cleric casting and 6d6 sneak-damage with a complete skill-progression.
a good thing would be the knowledge-domain, otherwise you wont have access to knowledge(religion) and epic spellcasting.
Dark Mask is a drow and half-drow 5 level prestige class from "Lord of Darkness" pg. 33. Spellcasting progression in existing class, a few cool abilities.
"...a darkmask is a divine spellcaster skilled in the arts of hiding sneaking and stealing."
ND = Nar Demonbinder from "Unapproachable East", pg. 25. 7 level prestige class, "Master of the black art of demon summoning and binding."
Also mentions the Black Flame Zealot:
If you don't want to be a drow of half-drow, and care more about skills then casterlvl's, you could try the "divine assasin", the black flame zealot(bfz):
rogue 1/cleric 3/rogue 1/bfz 10/ND 1/AT 4
This also gives you full skill-progression, 6d6 SA and a "lowly" clvl 12. But you also get a death attack DC 20+int mod, immunity to fear, dimension door 1/day, 1 flaming weapon and that weapon also being flaming burst 1 min/day and you immolate someone you kill with your death attack or with your sneak attack.
N.B. you also need the magical training with this build and you need Kossuth as patron.
N.B. 2 you can sacrifice the ND and AT lvl's for 5 lvl's of assasin, then you'll loose 4 clvl's, but gain some assasin spells, 1 SA die and up your death attack DC to 25+int.
N.B. 3 it seems the best way to be a divine trickster if you don't want to be a drow/half-drow or an assasin would be: clr 7/rog 1/GT 1/ND 1/AT 10
And the DarkMask:
Ninja1 / Rog1 / Cleric3 / DarkMask5 / MasterofShrouds9 / Hierophant1
8th Level Spells, BAB +15, +3d6 SA, Hierophant Divine Reach Ability for Inflict Wound Spells with SA As a variant, swap out 5 levels of MoS for 4 of Divine Oracle to get Evasion, UncDodge progression, divinatory stealth spell bonuses. All nice.
And Spellfilch from Dragonlance Campaign Setting:
Cleric 8/Rogue 3/Spellfilch 9 or Cleric 7/Rogue 4/Spellfilch 9
Spellfilch is in Age of Mortals (DLCS Companion), only one drawback, half caster progression (for either Arcane OR Divine)
Progression: Cleric 6/Rogue 3/Spellfilch 9/Cleric 7 and 8 (Cleric Caster 13) or Cleric 3/Rogue 4/Spellfilch 9/Cleric 4-7 (Cleric Caster 12)
Use Nar Demonbinder is tacky, but I guess it works... But it isn't much of a Trickster because the Arcane Trickster was written to add Arcane Spell Levels (I swear they left out arcane from the table for space issues)
And Cave Stalker:
Enter the Dwarf ....
Cleric4 / Ninja3 / CaveStalker5 / NarDemonbinder1 / ArcaneTrickster6 / MasterofShrouds1
** Cave Stalker is a PrC from Dragon Magazine #292 **
* BAB +13
* 7th Level Cleric (13 Levels) & 4th Level NarD Spells
* +7d6 SA
* Travel & Trickery Domains
* CS Goodies = +2 to Stonecunning Checks, Meld Into Stone WIS Mod. +1 / Day, +20' Darkvision, Hide/Survival/Spot as class skills.
Cave Stalker was originally made to accomodate a Dwarf Ranger/Rogue build, but serves well in a DT build as well. In fact, this build also gives you 9 levels of the Survival skill as a class skill (Track is a CS pre-req. feat), so you can act also as the party Tracker as well.
It's not a power-build, but it has a nice compromise of BAB, SA dice, & spellcasting prowess to make it a decent party ombudsman.
And the Suel Archanamach:
Whisper Gnome (Cha 10+ to get Mage Hand as SLA) Chaotic [whatever] alignment
Cleric 4/Rogue 4/Suel Archanamach 4/Arcane Trickster 8
7d6 SA
Using frac bonus' from UA will change how the Suel Archanamach progression works.