The following is my potential CD conversion of PF's Alchemist class. This would be another base class.
Source:
www.d20pfsrd.com/classes/base-classes/alchemist/AlchemistHit dice: d8
Alignment: Any
Proficiencies: Simple Weapons, Light Armor
Skill points: 6 + Int modifier
Base Attack Bonus: 3/4
Primary Saving Throw(s): Fortitude, Reflex
Class Skills: Appraise, Craft Weapon, Craft Trap, Disable Device, Heal, Knowledge (Arcana), Knowledge (Nature), Listen, Open Lock, Search, Set Trap, Sleight of Hand, Spellcraft, Spot, Survival, Tumble, Use Magic Device
Abilities:1: Alchemy, Bomb 1d6, Brew Potion, Mutagen
2: Discovery, Use Poison
3: Bomb 2d6
4: Discovery, Uncanny Dodge
5: Bomb 3d6, Resist Poison
6: Discovery, Cognatogen
7: Bomb 4d6
8: Discovery
9: Bomb 5d6
10: Discovery, Venom Immunity
11: Bomb 6d6
12: Discovery, Greater Mutagen
13: Bomb 7d6
14: Discovery, Persistent Mutagen
15: Bomb 8d6
16: Discovery, Grand Mutagen
17: Bomb 9d6
18: Discovery
19: Bomb 10d6
20: Discovery x2, Awakened Intelligence
Epic:
21: Bomb 11d6
22: Discovery
23: Bomb 12d6
24: Discovery
25: Bomb 13d6
26: Discovery
27: Bomb 14d6
28: Discovery
29: Bomb 15d6
30: Discovery
Alchemy (Su): Alchemists can fashion magical potion-like extracts in order to store spell effects. In effect, they prepare their spells by mixing ingredients into a number of extracts, then "cast" the spells by imbibing said extracts.
Extracts behave like spells in potion form, and thus can be dispelled by dispel magic, using the Alchemist's level as the caster level. Unlike potions, extracts may have powerful effects and duplicate spells that potions could not.
An alchemist can create a number of Extracts a day, as shown on the table above.
An alchemist has a book of formulae that detail the Extracts an alchemist can create. They begin with 2 formulae in their book, and gain an additional formula at each level increase. Additionally, Alchemists can learn additional formulae much like a Wizard adds additional spells into their spellbook.
To learn or use an Extract, the Alchemist must have an intelligence score equal to 10 + the Extract's level.
The DC for any Extract requiring one is 10 + the Extract's level + the Alchemist's Intelligence modifier.
Implementation Notes: Basically this works like a Wizard spellbook, but only has 6 levels and uses an altered spell list, provided below. Although NWN will treat this as "spellcasting", for the purposes of RP, you are not casting spells, you are brewing and imbibing potions.
See the Alchemical Formula list below for a list of available Extracts.
Bomb (Su): Alchemists are adept at quickly mixing volatile chemicals and other reagents into alchemical bombs that they can then throw. An Alchemist can use Bombs a number of times per day equal to their class level + Intelligence modifier.
Using a bomb requires a standard action and provokes an attack of opportunity. Thrown bombs have a range of 20 feet and require a Ranged Touch Attack to hit. Bombs do 1d6 Fire damage + 1 per Intelligence modifier. Bomb damage increases by 1d6 for every odd Alchemist level. Those caught in the blast are allowed a Reflex save for ½ damage. The DC for this save is 10 + ½ the Alchemist's level + the alchemist's Intelligence modifier.
Discoveries may modify Bomb's effects.
Brew Potion (Ex): At 1st level Alchemists receive Brew Potion as a bonus feat. An Alchemist can create a potion from any Formula they know up to level 5 that is capable of being brewed into a potion. Brewed Potions imbibed by an Alchemist gain a CL bonus of ⅓ the Alchemist's levels.
Mutagen (Su): At 1st level the alchemist learns to create a mutagen that they can imbibe to increase their physical prowess at the cost of their mental abilities. Only one Mutagen may be active at any given time. Mutagen grants a +2 Natural Armor bonus, and +4 magical bonus to the chosen physical ability score. The associated mental ability score receives a -2 penalty.
Depending on the physical ability score chosen, the following mental ability score is penalized:
Strength > Intelligence
Dexterity > Wisdom
Constitution > Charisma
Duration is 10 minutes per Alchemist level.
Implementation Notes: This line of abilities may need the most tweaking. As we saw with Rage, raw ability gains are not super useful on CD, especially at higher levels.
Cognatogen (Su): As Mutagen, but inverts the abilities, boosting mental ability scores while penalizing physical scores.
Greater Mutagen (Su): Increases the Mutagen Natural Armor bonus to +4, and the ability score bonus to +6.
Grand Mutagen (Su): Increases the Mutagen Natural Armor bonus to +8, and the ability score bonus to +8
Persistent Mutagen (Su): At level 14, the effects of a Mutagen (or Cognatogen) last for 1 hour per level.
Discovery (Su): At 2nd level, and every 2 levels thereafter, the Alchemist makes an alchemical discovery. Discoveries may only be selected once. Discoveries that modify bombs do not stack. The DC for any Discovery that calls for one is 10 + ½ the alchemist's level + their Intelligence modifier.
Use Poison (Ex): At 2nd level, the Alchemist becomes adept at using poisons to coat their weapons, and will never accidentally poison themselves while applying poison.
Resist Poison: At level 5 the Alchemist gains a +4 bonus to Fortitude saves made vs poison.
Venom Immunity (Ex): At level 10 the Alchemist becomes immune to poison.
Awakened Intelligence (Su): The Alchemist gains +2 to their Intelligence score.