Boreas: You mention Energy Drain in your post, but are you actually thinking of sacrifice instead? Because I think many of us would agree that Energy Drain doesn't need to be boosted in any way
Sutek: I like Reputation, too. But I guess we'll just have to agree to disagree on Corruption
. Interestingly, Oriental Magic has what is probably the strongest attack spell in Conan, namely Yimsha's Carpet. You mention using Corruption as a limiting factor. Does this mean you might run Corruption as demonic taint only, if these problem abilities were somehow balanced?
Thulsa: I'd like to know which spells do you think should require a Corruption save in addition to Energy Drain? And if Energy Drain causes Corruption, then sacrifice should cause Corruption as well, seeing as they're both described together and sacrifice is pretty much a "greater" Energy Drain. I'd say Power Transfer (AE, pages 186-187) is also similar enough to warrant Corruption with this interpretation, and if you disagree, acolytes could be used as Corruption-filters by Transferring the PPs they Drained to you. Now if the entries for say, Energy Drain, Ritual Sacrifice, Opportunistic Sacrifice, Power Transfer, and Bleed Dry all described a Corruption save, I'd agree that leaving out mention of a Corruption save in the entry for Tortured Sacrifice would most likely be an error. But since none of these nor any of the many spells that require a sacrifice or treats the victim of the spell as one mention a Corruption save, and a lot of instances that support the demonic taint approach made it into AE and SoS, I'd say it's extremely unlikely this is an editing mistake, at least.
If Ian Sturrock wanted very flexible Corruption rules, he could have easily expressed this with a single sentence. And some kind of ballpark DC wouldn't have hurt, either. Now I can't prove he didn't want flexible rules, but I'd say "sorcerous practices" almost definitely refers to Vampire Transformation and Demonic Pact, so at least there is a reason for that part of the sentence to be there.
Breaking down Energy Drain, I can think of 4 things that are characteristic to this ability.
1) It's arguably evil, but we already agree that evil alone is not enough, so this isn't what makes it Corruptive.
2) It gives the sorcerer 1d4 PPs, but Greater Meditation and Debaucher generate even more PPs, and they don't require a Corruption save from the sorcerer. Greater Meditation is even anti-Corruption, so I'd say gaining PPs isn't Corruptive either.
3) It does 2d6 temporary Wisdom damage, or 1d4 PP damage. Defensive Blast and many spells have arguably much more drastic effects on their targets than this ability. Should the use of all of them also cause Corruption?
4) It's arguably use of magic, but most spells would probably qualify as a "stronger" use of magic. Energy Drain is after all a minor touch effect that any lowly 1st-level sorcerer can use at will. Most spells are more extensive regarding many of these parameters: Effect, PPs involved, range, area, and duration. Should the use of these spells cause Corruption?
I'll finish with an example: Sorcerer A ("neutral alignment", 0 Corruption, Stygian) has somehow come upon his powerful enemy, the now helpless Sorcerer B (0 Corruption, 50 PPs stored right now). In case you think 50 PPs is too much, it could just as well have been two sorcerers with 25 PPs each. Sorcerer A decides to Energy Drain Sorcerer B, both to gimp him and because he could use the PPs. Even if Sorcerer A has a slightly better than 50% chance of making the save, he will still likely end up with 10 Corruption because of the save penalty from current Corruption and likely Insanity. Do you think it's reasonable that an uncorrupted "neutral" sorcerer should become extremely evil, get a major insanity, warp into a mutant, become permanently possessed by a demon, and afflict anyone in close contact with Corruption, all after only 20 rounds (2 minutes) of stealing PPs from a rival sorcerer?