Suggested LA for template in d&d 3.5?

[MonkeySage]

This form of undead is created when the host of a certain form of spiritual possession is killed. The spirit reanimates the body, transforming it into a larger, more ferocious version of it's living self. It retains all memories, gains razor sharp claws and a mouth lined with razor sharp teeth.

Hit Dice
Increase all current and future Hit Dice to d12s.
Speed
Same as the base creature.
Natural armor increase +6
Gains claw attack 1d8
Gains bite attack 1d8
Special Attacks: Charm (Su)- 10 + 1/2 HD + Charisma Mod Will Save DC
Poison (Ex) - 10+ 1/2 HD Fort Save DC, on successful claw attack. 1d6 Con, 1d6 Wis
Secondary Damage 1d6 Wis

Special Qualities: Damage Reduction 10/Magic
Fast Healing (Ex): Heals 5 points of damage every round as long as it has 1 hit point. After being reduced to 0 or lower hit points, it turns to dust. The spirit then searches for a new host.
Resistances: Cold 10 and Electricity 10
Abilities: Str +4, Dex +2, Int +2, Wis +2, Cha +6
Skills: +8 Racial Bonus on Bluff, Listen, Sense Motive, and Spot Checks.
Feats: Improved Initiative
LA:

I could not find a creature that best suited my current scenario, so I wrote one up myself. The scenario is that the players haves stumbled into a murder mystery: The monks of this isolated monastery have a killer among them. An evil spirit has possessed one of their own, feeding on malicious thoughts, augmenting them into murderous urges.
If the killer dies, the spirit takes over and reanimates the body, turning it into the undead creature above.

The spirit is mostly motivated by sadism.

Now, I wrote this up in a hurry so it's probably crap. I'm also somewhat new to homebrewing. But maybe you guys have suggestions to make it better?

Mostly I would like to know what potential Challenge rating to give it. The base creature is a level 2 human monk.