Still fine-tuning but here's the start. Disclaimer: I have not actually leveled one of these in a while, this was based off experiments while ETRing last night. I can hopefully get a bit better in a few days when I have some time to dedicate:

Assuming +7 tomes or better:
16 STR
18 INT
Rest into CON

Lvl 1 TWF / Quicken
Lvl 3 Weapon Focus: Slashing
Lvl 5 (Class) Extend Spell
Lvl 6 Power Attack
Lvl 9 Power Critical
Lvl 10(class) Maximize
Lvl 12 Imp THF
Lvl 15 Cleave /(class) Maximize
Lvl 18 Great Cleave
Lvl 20 Mental Toughness or whatever

Spells:
I'm not going to go through every single spell you might want at every level, but here will be your most useful:
lvl2 - Lesser Death Aura/Fog Bank(for miss chance)
lvl3 - DISPLACEMENT!!!
lvl4 - Death Aura/Negative Energy Burst(Prioritize these), then Stoneskin, Wall of Fire, and Ice Storm (DDoor is also nice)

When you hit 4th lvl spells at lvl 7 is when the build really starts to work. With Extend and Quicken going, Death Aura and Lesser Death Aura active, the main spell you're going to cast is Negative Energy Burst for a quick self-heal. You mostly want buffs like stone skin, and area-effect spells like Wall of Fire, Acid Rain, Ice Storm, etc. Fog Bank and the various other "% miss chance" spells are fantastic for survivability.

Enhancements:
I can work up a more detailed breakdown time permitting, but 3 trees are key:

Harpers - Int-to-hit/Int-to-dmg, and that's it
Palemaster - some undead shroud to let heal from negative energy + more
Eldritch Knight - elemental damage + SLAs(Imp Mage Armor & Imp Shield)

Will continue to fine-tune as more time becomes available. The big problem is BAB, which badly gates the THF feats. If anyone has any suggestions I'm happy to workshop this.

If you're going purely 1-20 (really 1-18)

Take a level of barb first.

if you don't run casters, the 12/6/2 stick isn't bad. not my original idea at all, but i tried a version of it and it ran fast which is all i really care about in a 1-20 and tr life. the rest takes care of itself

r/b/b/d/r/r/dx4/r/r/d/rest r

most important bits:

- stick speed #1
- temp hp #2 - never let go of w key
- first level shillelagh
- trip dc stuff
- t5 thief acro by 12

in that order, imo, though ill admit others disagree

not a lot of good staves in epics made of wood so i imagine other splits do better there

you got epic bloom and...

you got epic bloom

man, if you could convince the devs to add gunga grip to the game as a feat...

I think the best way to get pl’s does not revolve around using a single character...