Need help with Assassin optimization

[Quietus]

So, here's what I'm working with so far : I've got my poor little cliche halfling rogue, currently an NE worshipper of Nerull, and his talents run towards the so far frighteningly-effective method of "Sneak up and sneak attack". He's aiming toward being his order's primary method of "trash disposal", so to speak, and should be able to manage fairly well at that.

I've already got his base build laid out; Standard scout/rogue skill setup, max ranks in spot/listen/search/hide/move silently/disable device/open lock/disguise/etc, with a little dabbling in Use Rope and Poisonmaking for kicks. High int and dex, decent for the rest of my stats - we use a fairly high 40 buy.

What my major problem is right now is this : I'm expecting to pick up five levels of Rogue now, and follow that with ten levels of Assassin. That leaves me five levels to play with afterward, to help augment what I've already got going. I've got TWF right now, and I'll be picking up Weapon Finesse at 3rd and probably Practiced Spellcaster come 6th so my duration on my Assassin spells doesn't blow. I'll be picking up ITWF/GTWF at higher levels, and have a couple other feats to play with. What I'm mostly looking at, however, is the last five levels.

The main thing I want from those levels is full base attack advancement. My preference would be to find a class with nice skills, full BAB, and at least 2d6 sneak attack over the first five levels. I've only got a couple of feats to play with in the meantime, and most of my skills will need to be fed into the grinder, so if any particular class has a lot of requirements that I won't meet maxing out what I've already got up there, they have to tie into the "Harbinger of Nerull's Final Rest" theme I'm building. I've considered Blackguard (Power attack and improved sunder hurt too much), and the Daggerspell Mage, but those just don't suit too well. Invisible blade is sexy in the extreme, but I need more than 2 skills per level - and I'd like for at least SOME of my current class skills to remain class when I start going past 15.

I'm also open to suggestions for a short 2-level dip with full BAB; I can take another 3 levels of Rogue while working my way up and grab Improved Uncanny Dodge, full BAB for those levels, another d6 of sneak attack, and the minor bump to my trap sense. Plus the sweet, sweet rogue skills, of course.

Any ideas?

[Penguinizer]

If you have ToB, take a couple of levels of Swordsage, take all the Shadow Hand skills you can. They get some nifty maneuvers.

[Quietus]

If you have ToB, take a couple of levels of Swordsage, take all the Shadow Hand skills you can. They get some nifty maneuvers.

No can do, don't have access to ToB. I could probably wheedle individual things in from the Complete books, but ToB is out.

[Penguinizer]

Ok, well, other than that, I got no idea...

[Fax Celestis]

Rogue 5/Spellthief 1/Assassin 1/Unseen Seer 10/Uncanny Trickster 3, and take the Master Spellthief feat.

Spellthief is in C. Adventurer, Unseen Seer is in C. Mage, and Uncanny Trickster is in C. Scoundrel. Focus the Unseen Seer "+1 spellcasting" on Assassin and Uncanny Trickster "+1 existing" on Rogue.

You'll end up with BAB +13, +10d6 Sneak Attack, full Assassin casting, and the ability to steal 7th level spells (via Spellthief and the Master Spellthief feat). It's not a bad build. I have better, but you're not allowed ToB and it's really really early late.

Another good call is Rogue/Assassin/Unseen Seer/Abjurant Champion, mix and match to suit. It's a bit more frontliney than the above build.

[Skjaldbakka]

Another Build possibility:
Cleric 3/Rogue 2/Black Flame Zealot 10/Assassin 5

Gives you 13 levels of cleric casting, +9d6 sneak attack, and a death attack of 15+int mod.

[Fax Celestis]

Another Build possibility:
Cleric 3/Rogue 2/Black Flame Zealot 10/Assassin 5

Gives you 13 levels of cleric casting, +9d6 sneak attack, and a death attack of 15+int mod.

Archivist'd go better in that build, for Int-synergy.

[Quietus]

I'm thinking I might have a bit of trouble convincing my DM to let me take classes like Uncanny Trickster and Unseen Seer... they both appear to give a LOT of advantages. You barely lose anything by entering the Uncanny Trickster prestige class, just gain some extra skill trick stuff, and unseen seer is just.. awesome. In all honesty, the only thing I can say about that class is that it doesn't get a good HD, but for everything else it offers, it's incredible.

Black flame zealot... what book is that in?

[Dant]

Complete Divine. It's a sort of divine assassin evil dude prestige class. I actually kind of like it. As a bonus, I seem to recall the capstone immolates the bodies of those you kill with death attack and makes it impossible to resurrect them. Very convenient.

[Person_Man]

I'm not a fan of the Assassin. His spells and Death Attack stop scaling beyond ECL 15, and Death Attack really isn't that effective anyway against most enemies. If you do go with it, I suggest you finish off your last levels with Hexblade with the PHBII variant and the Paladin of Tyranny. Collectively, they'll impose a -4 on your enemies' Saves, making your Death Attack and spells somewhat more effective.

I like Fax's Spellthief build. It has a lot of different options built into it, so you're unlikely to get bored.

The generic skills and kills TWF build is currently Rogue 3/Swashbuckler 17 with the Daring Outlaw feat from Complete Scoundrel, which allows you levels to stack for Sneak Attack. 19/20 BAB, 10d6 Sneak Attack. Use TWF with Improved Unarmed Strike or Oversized TWF, and Power Attack can apply to all of your attacks.

I'm also a huge fan of the Psychic Rogue, and to a lesser extent, the Psychic Assassin, which gives Sneak Attack, Death Attack, and 1/2 manifester progression, which is superior to the normal Assassin's spells. Either class will grant you the Mind Cripple ability, which deals 2 points of Int damage (no Save) every time you Sneak Attack someone. Hugely effective against low Int monsters and Wizards.

[Quietus]

I'm not a fan of the Assassin. His spells and Death Attack stop scaling beyond ECL 15, and Death Attack really isn't that effective anyway against most enemies. If you do go with it, I suggest you finish off your last levels with Hexblade with the PHBII variant and the Paladin of Tyranny. Collectively, they'll impose a -4 on your enemies' Saves, making your Death Attack and spells somewhat more effective.

I like Fax's Spellthief build. It has a lot of different options built into it, so you're unlikely to get bored.

The generic skills and kills TWF build is currently Rogue 3/Swashbuckler 17 with the Daring Outlaw feat from Complete Scoundrel, which allows you levels to stack for Sneak Attack. 19/20 BAB, 10d6 Sneak Attack. Use TWF with Improved Unarmed Strike or Oversized TWF, and Power Attack can apply to all of your attacks.

I'm also a huge fan of the Psychic Rogue, and to a lesser extent, the Psychic Assassin, which gives Sneak Attack, Death Attack, and 1/2 manifester progression, which is superior to the normal Assassin's spells. Either class will grant you the Mind Cripple ability, which deals 2 points of Int damage (no Save) every time you Sneak Attack someone. Hugely effective against low Int monsters and Wizards.

I'm trying to keep away from psionics for now, as the DM I'm running with isn't exactly the most experienced - the simpler I can keep things for him, the better. Adding power points and manifester stuff to the mix isn't going to help that... though the Mind Cripple sounds sexy as anything.

The reason I'm heading into Assassin isn't for the Death Attack, though that IS a nice bonus - my main target is the sneak attack, poison use (flavor, mostly, I'm not worried about DC 10 reflex saves to not poison myself, I've got +7 to reflex already), and spells. I'm well aware that the spell list for the Assassin isn't necessarily spectacular, but getting most of the Rogue benefits, as well as things like DimDoor, greater invisibility, and modify memory... I like having those options available to me. Besides, the death attack doesn't have to scale past level 15; If it were a normal ability it'd have the same DC come level 20. It just hits its max earlier this way.

I'll have to look into the hexblade and paladin of tyranny stuff, as well as that black flame zealot.. I do like me some save penalties, and sneak attack is great. This char is travelling with a human cleric of Nerull, so I'd rather reduce my opponent's saves than increase the DC's. Of course, doing both is never a bad thing.

And yes, Fax's spelltheif build does look like a lot of fun... but I think it'd be a bit much to hit an apparently inexperienced DM with, even if I did think I could get an okay on the PrC's.