Apart from bad luck or distracted play of course, it feels like I'm hacking the game when using it. So I beat Dredmor the first time (yay) today, with this build Daggers Bankster Piracy Magical Law Dual Wielding Assassination Burglary The original idea was to exploit Magical Law and Piracy for 100% counter with Objection to support the Bankster debuff removal, and that worked well enough, though by the time I reached floor 11 I had ~90% passive counterattack, so that didn't end up being a good use of MP, and as a result I just wasn't getting hit enough to ever use Fiscal Hedge, except as a failsafe on big bosses. What I really ended up using to the exclusion of all else, once I got below lvl 10, was Gag Order and Polymorphic Injunction. Yes, I had a lot of from all those Rogue skills and that helped keep the cost down, but corruption monsters were a total nonissue. Does it cast corruption, or nuke in some nasty way? Gag it. Does it corrupt by touch? Rewrite it. dlvl13 was a snap. Gag archmages in sight, move away for them all to die, then move in and clear everything else. I could have done the same splashing this into an all Warrior build, and being more consistent about drinking, and could have done it all the way down. I can't think of a reason to not include it in every build, frankly. There's no negatives, unless you count being unable to use them as often as a negative. Doesn't seem like that big a negative, though. Black Lotus is still a must have, even if you can only have 1 in your deck.
Well, I was asking the question from an efficiency perspective, but I should have specified that. This is, of course, a single player game, so balance isn't particularly critical, but I don't see how this is less unbalancing than Egyptian Magic was, even if it isn't as flashy.
What I mean is, some people just like playing with different kinds of builds. And some players don't want "the easiest" game, but instead they want to struggle for their survival only to triumph in the end. Combine the two and you have a reason not to include this skill tree in every build. It was like Promethean Magic before it got nerfed (repeatedly). Okay, it was cool, and it was powerful, but even back then I would rather take Burglary or Master of Arms over Promethean Magic, effectiveness be damned. Sure, if it is your first time and you really want the achievement, stacking on synergetic and powerful skills is the way to go, but after that (or even before that, if you don't care about the achievement) it's not about the fact of defeating Dredmor but rather about the journey to the bottom of the dungeon. You did not play "Planescape: Torment" to defeat the Transcendent One - you did it to take the Nameless One through his journey to finding out who he is, and who he was, and the same thing happens here. For victory without struggle is empty and boring, because it only multiplies the value of good events that you experienced and with nothing experienced you would gain nothing after winning. Heck, imagine if Fallout 1 had a combination of traits you could take so that your character would be able to find a spare filter in the Vault. Okay, cool, you just won the game in a few minutes, but you would only feel disappointment after that.
I do understand that people don't necessarily want to play The Best, and want to try and make a less optimal thing work. I'm the guy that started the Pimp My Random thread after all (which I should eventually get back to, Torchlight and GW2 have taken up a lot of time). I definitely was not trying to say that "you all are idiots for not using this" or even complain about Egyptian Magic being nerfed. I only wanted to check whether there was some aspect of the skill that I'm missing that balances it. Checking my math, as it were. And if my math wasn't wrong, argue that this ought to be on the nerf block for the aforesaid reasons.
I know you weren't. And well, the ultimate spell tends not to work well if you don't have any really abusable cooldown-based abilities, and in such a case you would be better off just getting something else instead of this. And while some of the other spells in it are really useful, there are other skill trees that have equivalent spells while also having something else so you might not want to take that particular skill tree all the time. I just am on a writing spree and it looked like an occasion to write some.