Red Wizard build direction.

[Aurali]

From a lore perspective, Thayans as a whole do not condone blood magic so I would not recommend a Red Wizard to take Blood Mage. I cannot speak on behalf of the DMs but their current ruling is that you can only access the Shadow Weave if you have Shar’s blessing and maintain the secrecy of its existence.

As for build advice for a DC caster, I would second the Wizard/RW/Archmage. The archmage would allow you to pick up Spell Like Abilities for those nice spells you may not have access to. Plus, you could conceivably take 9 wizard/4 RW/7 Archmage before 20 to get 3 bonus epic feats. Starting out as human, you’d need all the bonus int you could get for your DC and spell slot bonuses. If you do it right, you could end up with a 34 int so along with spellcasting prodigy, you can pick up another 9th level spell slot.

[Incarnate]

I'm thinking W5 / RW5 / AsoC10 / ACM10.

The reason I'm thinking Arcane Scholar 10 is simply because it enables one to empower, maximize and quicken more spells - which really means you get more out most castings. The archmage 10 reasons are like ones you stated, but there are some nice high arcana options that could be considered for their utility or effectiveness they impose.

[Sun Wukong]

As for Arcane Scholar, sure, the metamagic does let you expand your spell selection in a sense... But it still works far better on a sorcerer with spontaneous spell casting. Because if you are actually spamming direct damage spells, you do not want to waste a high spell level spell to finish a mob already on low health. And generally speaking, a CR 15 mob against a level 20 DC caster will eat something like 3+ Empowered Chain Lightnings before finally going down.

The direct damage spells just do not deal enough damage, at least not without first gathering a mob of 20+ to be spammed out in one go.

Save or die spells are the better choice.

And even that in mind, grinding to level up works easier if you have summons, and perhaps make use of that Polymorph Self or Shapechange.

[Incarnate]

I kinda wonder, if the ACM Arcane Fire actually really worth it in NWN2.

Basically put, at ACM 10 the potential damage is 11D8 and the maximum 19D8.
The 11D8 ~ 8-88.
The 19D8 ~ 19-152.

Depending on what spellslot is sacrificed it could deal more or less than what certain spells for the specific spell level would be able to output - meaning certain spell slots would most likely not be used because there are spells that can out put more than that. Plus getting the ability also comes at the sacrifice of a 9'th level.

[Sun Wukong]

I think you get 10d6 damage from cantrips. Could be wrong though.

[Incarnate]

I think you get 10d6 damage from cantrips. Could be wrong though.

Yeah, thats indeed very powerful considering no cantrips would ever be able to deal that amount of damage. But still, is it worth a 9'th level spell?

[chad878262]

I wouldn't necessarily say it's 'very powerful'... You only get 4 cantrips per rest, 4 casts of 10d6 isn't earth shattering... I would say it's more appropriate that it at least gives some use out of cantrip outside of occasional RP use.

[Sun Wukong]

Arcane Fire might have a use in the situation where the rest of the party goes down, and the sole surviving wizard needs to deal damage at the ancient black dragon to finish it off - and their entire spell book happens to be nothing but buffs. In this particular case, I can see a use for the Arcane Fire.

Other than that, a spell like ability might be more useful, or just about anything else.

[Incarnate]

I wouldn't necessarily say it's 'very powerful'... You only get 4 cantrips per rest, 4 casts of 10d6 isn't earth shattering... I would say it's more appropriate that it at least gives some use out of cantrip outside of occasional RP use.

Well, comparing the potential damage with the arcane fire for a cantrip for an ACM 10, its quite a lot - and its 10d8 not 10d6, not a huge difference but still - (at least thats what the wiki says).

Example:
Ray of Frost: 1d4+1 damage ~ 2-5 damage.
Arcane Fire (Cantrip level): 10d8 ~ 10-80 damage | If critical: 20-160 damage

The maximum damage is 16x more than what the cantrip spell could ever do, plus at actually has the potential chance to be a critical, and if so the maximum damage is actually 32x more than what the cantrip could ever do. So I'd say its potential is very powerful in comparison, even though the chances of it becoming a critical is very low, 16x times more is still something. Even if it was just average damage, which would be around 50 points of damage for the arcane fire and 3 for the cantrip, the damage would still be 16x higher than the cantrip. So 4 cantrips converted to arcane fire would be 200 points of damage on average, as opposed to 12 on average. If not powerful, then at least its very efficient use of those 4 cantrips, but quite important to also remember its at the expense of a 9'th level spell.