Help with a modified assassin

[D3agle93]

I have recently started playing my first game of d&d and am looking for advice in building my character. The game world is a customized post-apocolyptic earth and my character is currently a level 3 Swashbuckler. I was intending to multiclass into Rogue and eventually a modified non-evil Assassin. My character has finesse with a rapier and focuses more on rapid, accurate damage from the shadows, rather than a stand up fight. Some research I have done myself has me interested in a prestige class called the Avenging Executioner, but I am not entirely sure how to implement the class, if I should include it at all. I know very little about d&d and all its finer points so any assistance would be greatly appreciated.

[Emperor Tippy]

Swasbuckler 3/ Factotum 8/ Invisible Fist Decisive Strike Monk 2/ Assassin (or Avenger (http://www.wizards.com/default.asp?x=dnd/prc/20070401a) ) 1/ Swordsage 6

Take the feats Kung Fu Genius, Craven, Darkstalker, and Shadowblade.

When you want to deal damage use Cunning Surge as your initial move, move within range of your enemy, use your full round action to use Decisive Strike, spend all of your Inspiration points on Cunning Surge + Cunning Insight.

Decisive Strike doubles all damage you deal against that foe for the rest of the round. Cunning Surge can give you another 5-10 attacks against said foe. Craven adds your HD to damage if those attacks are sneak attacks. Shadowblade adds your Dex to damage if you are wielding a shortsword (or a few other weapons) and are in a Shadowhand stance (which you will always be in). Swashbuckler adds Int to damage. Cunning Insight adds Int to damage again. Use a +5 Collision Shortsword for another +10 to damage. Spend your Swift action on Burning Blade for another +IL (13 at ECL 20) to damage.

Now double all of that. So each attack get's (potentially) +2xStr, +2xDex, +4xInt, +2xHD, +20, +26 damage; or with 30 Int, 30 Dex, and 20 Str at ECL 20 +156 damage per attack. And you are making potentially 10 of those in one turn, and potentially all against your foes Touch AC.

[Pluto!]

@OP, I'm not sure what kinds of advice you're looking for exactly, but maybe this handbook (http://www.minmaxboards.com/index.php?topic=8273.0) would help? I tried to be pretty thorough, but unfortunately wasn't directing it to new players, so some community assumptions and jargon probably snuck in. The guide at least might help you to structure a more concrete plan to discuss.

On Avenging Executioner, it's the kind of a class you have to go all-in on as soon as possible in order to keep its DCs relatively high and get use from the its abilities before every single monster has immunities to its class features. AE's a pretty reasonable class for a fear build (this handbook (http://www.minmaxboards.com/index.php?topic=8759.0) has some suggestions for making that work).

The Assassin's a capable class, but taken late in a build, its abilities look a lot less impressive than they do early on, so I think you'd do better to pick Assassin or AE and stick with it.

[PraxisVetli]

I respectfully and fearfully back everything Tippy just said.
Everything Tippy EVER says.

unless you're against making your DM cry.
Then you should probably ignore him.