Building NPC enemies?

[demonwalker]

I'm Gming a game of pathfinder for the first time, and I feel like I need some help building enemies that aren't monsters. Right now, I'm working on creating a (hopefully) recurring villain that the PC's will use to get information out of when he flees or dies. The goal is a Half Dragon (Copper) Magus with CR 6. Problem is, I have no clue how to go about doing that. I've looked up creating NPC's and feel like the heroic stat-line will work for him. Race isn't really a problem, just haven't decided what it will be yet. I have very little idea on how the Half-Dragon Template really works, other than it adds those abilities. The main problem being this:

A half-dragon retains all the special attacks of the base creature and gains a breath weapon usable once per day based on the dragon variety (see below). The breath weapon deals 1d6 hit points of damage per racial HD possessed by the half-dragon (Reflex half; DC 10 + 1/2 creature's racial HD + creature's Con modifier)

What I need to know pretty much is, what level will the NPC be, how many of those would be Half Dragon (If any), how many would be Magus, and what it's hit dice will be. The racial hit dice of the template is what is throwing me off, so help is appreciated.

In addition, for the BBEG, I'm not sure how to determine his ability scores. He will also be a NPC of some sort. Advice on how others normally decide that is appreciated as well.

[Coidzor]

X Magus Levels = X CR. So a CR 3 Magus should be a level 3 Magus, barring anything else going on.

Half-Dragon is a CR+2 template according to the pfsrd. (http://www.d20pfsrd.com/bestiary/monster-listings/templates/half-dragon)

So you want a CR 6 Magus with Half-Dragon as a template. Assuming the base race is Human or something similar that gives us X + 2 = 6, or 4 levels of Magus to play around with. This Half-Dragon Magus would have 4 HD from its 4 Magus levels, as Half-Dragon does not give additional HD to a creature.

What's the base race that you're applying Half-Dragon (http://www.d20pfsrd.com/bestiary/monster-listings/templates/half-dragon) to?

[demonwalker]

I was intending to use this custom class for it.
http://blackflamestudios.weebly.com/corruption-beast-template.html

If not that, I'd use Tiefling.

Also, I thought I read something on NPC's giving a -1 to CR? Or something else odd like that. I could be wrong though.

[Coidzor]

IIRC, you'd be giving him NPC wealth/gear as a 6th level Heroic NPC, but I'm not entirely clear on that front due to the template adding to his actual levels for total CR.


I was intending to use this custom class for it.
http://blackflamestudios.weebly.com/corruption-beast-template.html

That's a race that's calling itself a template, not a class. :smallconfused: A bit weird that it calls the race a template, but it seems to work.

Between the base race and Half-Dragon, that gives the character +10 Str, +6 Con, and +4 Int, so even going with Strength as the dump stat means it'll be fairly strong.

[demonwalker]

That's the intended goal. Since the main goal if for the PC's to destroy almost all artifacts, I'm hoping that they will come up with inventive ways of beating him that involves not being near him. Especially as only one of them it a non-caster class.

Edit: As for my other question, Do I just use the same NPC ability score system for the main villain, or is there a different system I should employ?