help with stealthy bbeg

[its_all_ogre]

the final 'boss' guy in a ruined city will be an advanced wight with several class levels and i want a bit of help building them up.
first up the guy is not meant to be a melee giant, it is a goblin ninja5/monk2/psychic warrior2/shadowdancer1

the idea is that this guy uses hide in plain sight to move around and has created a quite sizable force of wights and other undead due to plot devices.
as i use a house rule that gives monks full bab and the option to use wisdom as the active stat in combat the monk levels are not dead weight.

at present he stands as follows: str 10 dex 22 con - int 12 wis 22 cha 14
feats stunning fist, combat reflexes, speed of thought, up the walls, dodge, mobility, spring attack, side step charge.
skills: tumble +12, balance +12, bluff +5, climb +6, craft poison +9, escape artist +15, heal +6, jump +20, sense motive +10, hide +28, move silently +23, spot +11, listen +11.
powers from psychic warrior will be aimed at skate and something else, to boost movement or stealth, unsure what yet.
current plans for his equipment are boots of striding and leaping, cloak of elvenkind, periapt of wisdom +2, gloves of dexterity +2, ring of protection +1.

i'm giving this guy pc wealth to play with, he's been looting a city for the past 5 years and has been defeating living patrols and creatures and looting their stores. at some point there will be a showdown in this city in an old abandoned temple where there are pools of unholy water which he and his undead use to repair themselves.
hopefully when they finally come face to face for the showdown they'll be level 9-10 and i'm not entirely sure what else i can do to this guy to make him a bit more survivable.
he's going to do hit and run attacks on the pcs occasionally and may be encountered randomly throughout the city.
books available are core, phb 2, comp adventurer.
thanks in advance!

[its_all_ogre]

nothing?

[Allis]

If he has this abandoned temple as his strongholt, you might want to build in defences, traps and the likes. That would be a reasonable thing to do, I guess, for a stealthy character protecting his loot.

[its_all_ogre]

there is totally going to be some nasty traps around the temple, all built around poisons or other things that will not hinder undead at all.

i just meant on the guys build really, seems solid to me personally, he'll be able to level drain with a punch combined with sudden strike to do some damage and scare players enough.
their main issue will be forcing him into a showdown due to his hide in plain sight ability. but by making him reliant on his lair to repair himself, no umd, he has a reason to stand and fight.
he's actually awaiting the return of his necromancer friend that he was a bodyguard to in life, unknown to him this necromancer is not returning, but he is building up a force of wights to further his boss' goals once he does return.