I'm DMing an alternate campaign for my group designed for times when 1 or 2 of the players cannot attend. The premise of the campaign is the PCs work for House Orien in a Planet Express-like capacity, making extremely dangerous deliveries all around Eberron, which should lend itself well to being an episodic campaign that fits in between games of the main campaign. I'm making a flavorful NPC based around the Blade of Orien Prestige Class (Dragonmarked, page 99) to help the PCs out when the group is short on players.
Books allowed: everything except books specific to a campaign setting other than Eberron
Stats: Rolled for all PCs and this NPC - 14, 13, 18, 11, 15, 16. The 18 was a 9 but we have a houserule that the lowest number you roll becomes an 18.
Feats: No flaws. Feats come at every odd level like Pathfinder. Power Attack is a non-feat that every character gains access to after 2 BAB since I feel generous to people who want to play melee brutes. All the Two Weapon Fighting feats are rolled into one feat that scales with BAB for similar reasons (Rangers get both styles and bonus feats to sort of compensate).
Skills: Cross-class skills are 1 to 1 just like class skills. Their cap is equal to character level instead of character level + 3. UMD/UPD are an exception to this. Balance and Tumble are combined into Acrobatics. Climb, Jump, and Swim are combined into Athletics. Hide and Move Silently are combined into Stealth. Listen and Spot are combined into Perception. Ride is lumped into Handle Animal. Having any of the old skills as a class skill makes the new combined skill into a class skill.
Restrictions: All 10 levels of Blade of Orien have to be used because I like the capstone ability to full attack at the end of a move action Dimension Leap. In general I want this guy to be helpful but not to overshadow the tactics of the players. I would prefer the Prestige Class be entered into as early as possible. The NPC will be leveled along with the players to keep him in balance with them when he's used.
