Optimising a Multi-Weapon Character

[Cogidubnus]

Gestalt Death Knight 20 (http://www.giantitp.com/forums/showthread.php?p=10352906)//Marilith 17 (http://www.giantitp.com/forums/showpost.php?p=8132375&postcount=246)
is a level 26 character. So, I need suggestions on good classes for those last few levels. Feats would also be appreciated (got up to Perfect MWF). I'm aiming for a really good multi-attacker, but I've already got that with 6 arms and MWF, so any suggestions are welcome, even if they just expand the ability set. Oh, and no Tier 1 classes.

The DM has ruled that there is a multi-weapon version of ANY two-weapon fighting feat. Also, I have the death knight frost specialisation, which reduces my penalties for fighting with multiple weapons by -1, allows me to use any 1-handed weapon in my off-hand and adds full STR bonus to off-hand attacks.

[Biffoniacus_Furiou]

You have 15 open class levels total. I'd take only nineteen Death Knight levels, to include ten War Hulk in Miniatures HB and six Fighter with the Dungeoncrasher ACF from Dungeonscape. Something like Marilith 17/ Death Knight 9// Death Knight 10/ Fighter 6/ War Hulk 10. Take the feat Knock-Back from Races of Stone, so every opponent you hit will be bull rushed back and if they hit a solid obstacle they'll take considerable damage.

With War Hulk 10 every attack you make will hit every opponent within reach, including AoOs, so with Perfect MWF, a Speed weapon in your main hand, and +16 BAB, that's five attacks per weapon or thirty attacks per round against everything you can reach. Sweep everyone into a corner and Dungeoncrash them against the wall until there's nothing left. I'd use six Kusari-Gama (DMG page 144-145), which is a light reach weapon so you'll suffer minimal MWF penalties. Knock-Down (http://www.d20srd.org/srd/divine/divineAbilitiesFeats.htm#knockDown) is also highly recommended, so every opponent will be knocked back and knocked prone, and if anyone tries to get up your AoO hits everyone in reach, potentially knocking everyone else back down again. If you can fly, you can just Dungeoncrash your opponents against the ground instead of into a wall. Take the feats Aberration Blood and Inhuman Reach (LoM) to get +5 ft. reach, and your natural reach will be doubled for using reach weapons.

[IthroZada]

A way to get Pounce would help you extremely. Be it through Lion Totem Barbarian, psionics, Maneuvers, or Shadow Pounce from Teflammar Shadow Lord from Unapproachable East.

[Gnaeus]

You have 15 open class levels total. I'd take only nineteen Death Knight levels, to include ten War Hulk in Miniatures HB and six Fighter with the Dungeoncrasher ACF from Dungeonscape. Something like Marilith 17/ Death Knight 9// Death Knight 10/ Fighter 6/ War Hulk 10. Take the feat Knock-Back from Races of Stone, so every opponent you hit will be bull rushed back and if they hit a solid obstacle they'll take considerable damage.

With War Hulk 10 every attack you make will hit every opponent within reach, including AoOs, so with Perfect MWF, a Speed weapon in your main hand, and +16 BAB, that's five attacks per weapon or thirty attacks per round against everything you can reach. Sweep everyone into a corner and Dungeoncrash them against the wall until there's nothing left. I'd use six Kusari-Gama (DMG page 144-145), which is a light reach weapon so you'll suffer minimal MWF penalties. Knock-Down (http://www.d20srd.org/srd/divine/divineAbilitiesFeats.htm#knockDown) is also highly recommended, so every opponent will be knocked back and knocked prone, and if anyone tries to get up your AoO hits everyone in reach, potentially knocking everyone else back down again. If you can fly, you can just Dungeoncrash your opponents against the ground instead of into a wall. Take the feats Aberration Blood and Inhuman Reach (LoM) to get +5 ft. reach, and your natural reach will be doubled for using reach weapons.

That is pretty impressive.

Personally, going from that start, I would go Death Knight 20/Rogue 5/Assassin 1//Marilith 17/Swordsage 9. Get some Shadow hand tricks to jump around the battlefield and to give you quick actions (and a chronocharm of the horizon walker), and some Tiger claw multiweapon fighting maneuvers, and each of your attacks will be doing +6d6 sneak attack damage.