Some feedback you should think about for building a Rogue/Wizard type...
- Wizard 18 brings you nothing, much better w/ W16/AT10.
- We do not have Persistent Spell on this server.
- Even though you lose CL30 you are still better off going SD3/R3/W14/AT10 (requires 19 DEX). You get CL28, but you get HiPS, making landing those RTA Sneak Attacks safer.
- As an Alternative, you could go W13 /A8/AT9. Assassin requires 8 Hide/MS, but this will get you CL 26 and HiPS without the DEX requirement. Plus with high INT your Death Attack will have a solid DC.
- Your BAB is going to be bad, Weapon Finesse is a wasted feat since you should be using magic for damage. Try getting a reserve feat like Invisible Needle.
- Toughness / Steadfast Determination. Not a terrible pick as with Superior Resistance you'll have ok fortitude save of ~20. However, there are probably better picks since your goal should be to take zero damage and use HiPS or Counter Spell to avoid having to make a saving throw. Still not a bad pick, but there are far better ones. Epic Toughness is a definite waste of an epic feat. Move Maximize to pre-epic and take two more great INT feats or epic spells such as Vampiric Feast (unless you don't want to for RP reasons, being CN).
- Greater Ruin or Damnation would probably be better than call lightning storm, if you don't want Vampiric Feast.
- While you are welcome to pick a specialist school, if you are new to magic, it might be better to go generalist with no opposition school so you can experience all the spells. 1 extra spell per level is nice, but you should at least understand what you are giving up.
- You don't need Silent Spell unless it's for RP purposes. You DO NEED Quicken...
- You need to max Hide and Move Silently.
Here is a CL30 Rogue/Wizard build with no HiPS:
http://nwn2db.com/build/?238747
I can't find a build with HiPS at the moment, but if you need a base build to go by let me know and I'll throw one up when I get a chance.
EDIT: made up a quick one...skills are incomplete and I may have forgotten something as I kind of threw it together, but did my best to keep most of your stats in tact...
http://nwn2db.com/build/?265179