This guide was made when Spleen did his 21:30 run:

"Promethian Magic - All the damage, best way to kill Dredmor. The Wyrm is overpowered and carries the whole run. Killer Vegan - I am extremely easy to kill, so animal immunity is very useful. Makes floor 7 a breeze and floor 9 less hellish. Golemancy - Though not shown here, the wall is (usually) vital to pin Dredmor in. Here I got a very lucky spawn. Leywalker - Mana. Mana Mana Mana Mana Mana. Magical Law - Gag Order is the only way to stop Dredmor from teleporting all over the place and generally wrecking you. Mathemagic - Zenzensomething gives a massive amount of damage and the teleports are very handy. A place to put loose skill points from later zoos. Blood Magic - Mana for every kill. Incredibly overpowered when dealing with Monster Zoos. Replaced Archeology with this because Archeology was doing nothing for me.

Strategy:

floor 1 - get the wyrm then rush onwards floor 2 - look for a zoo and/or The Baron floor 3 - look for a zoo and/or the Robo set piece (with the amulet) floor 4 - look for a zoo floor 5 - look for a zoo and Diggle Outpost set pieces for Heroic Vandalism bonuses floor 6 - rush onwards floor 7 - look for a zoo and grind; there are a lot of animal enemies to whom I am immune floor 8 - finish grinding floor 9 - avoid death and rush past floor 10 - get lucky and find Dredmor, pray he doesn't spawn right next to a door and one-shot for a humiliating defeat

Anything which improves magic damage or gives mana regen is a good pick-up. Orbs are very strong. A Pan-Galactic Gargle Blaster is vital to beat Dredmor in timely fashion, and any Mana Potions make killing him much faster. The game is inherently laggy as it forces you to watch all attack animations, so getting the wyrm off-screen and letting it take everything out decreases game time by a massive quantity. Other animation cancels include playing at ++ speed and attacking chests and Statues of Dredmor diagonally, as you miss out the melee attack animation. There may be an incredibly overpowered Wizardland code, but I do not know of any, so I have stayed away from the Lost wizard Keys."

He also said: "if you don't silence dredmor then he blinks and/or one-shots you; if you don't halt him then he punches you and one-shots you; if you don't kill him quickly then you run out of mana and he one-shots you."

And mentioned that: "The only difference between that^ and the 14:42 run is that i swapped blood magics for wizarding school."