Help with a Lizardfolk Assassin for PF

[Lionheart]

Hello all,

Once more, I'm looking for some help from the Playground for designing a not so BB EG for my regular PF game.

I'm trying to put together an NPC that has so far been referred to as a master assassin, the tales say that none have seen his true face and survived.

I'm trying to put the character together, and I just can't make up my mind on a build. The character is Lizardfolk, and fights with a scimitar (so the obvious choice is bard for dervish dance etc.) For base classes I'm leaning either towards Slayer for a full martial character or Magus or Bard for someone with a few more tricks up their sleeve.

Then I'm not sure if I want to go into Assassin or Shadowdancer, (or both?) Assassin adds a lot of Sneak attack and Death Attack damage, but I love the idea of Shadowdancer, perhaps a Dervish Dance bard (5) into Shadowdancer (10) and round off with the last 5 levels as assassin?

Sorry it's a bit of a rant, any help greatly appreciated.

Thanks

[the_archduke]

ophiduan (http://www.d20pfsrd.com/psionics-unleashed/races/ophiduan) stalker (http://www.d20pfsrd.com/path-of-war/classes/stalker)

[Grod_The_Giant]

Alchemist with the Vivisectionist archetype gets full sneak attack, a mutagen to buff his dex, and all the special tricks you could ask for with his extracts. Heck, he's pretty much the only class who can use poisons effectively. No PrC necessary- just load up on the right extracts and discoveries and slaughter away.

Is there a version of the poison dusk Lizardfolk in pathfinder, incidentally? Lizardfolk can make great melee Vivisectionists, but your plan (dervish dance) gives up most all of their bonuses.