Pathfinder 1E Prestige Class for a Evil Fight that uses deception?

Alright so I am currently looking for a good prestige class for my character but it's kind of hard because most fighters arnt really deceptive. I am a very very very very evil character along with my group. If it helps I openly worship the deity Bane (God of Hate and Suffering). What would you guys suggest?

Unfortunately, you are not giving us any information about your character's build to provide any kind of real help. Are you a fighter already? A rouge that wants to get in the middle of things? Also, what exactly do you want/need the prestige class to do? Is it to show off how evil your character is? We don't know and can't direct you in any meaningful way until we do. In addition, how you do want to be deceptive?

With that out of the way, a lot of people feel that the Pathfinder prestige classes fill very niche positions (mostly tied tightly to their AP lore). If you DM allows 3rd party Pathfinder or better yet 3.5 content you'll have much better luck finding the exact prestige class for yourself. If neither of those are acceptable options, I would advise looking at the other classes (which I feel is a superior option to Pathfinder prestige classes). Off the bat I would suggest the hybrid class Slayer. It comes with full BAB, a d10 HD and 6+Int mod skill points. In addition, it's Studied Target class feature is a weaker, but more versatile Favored Enemy.

If you can use 3.5 content you may wish to look at the following:
[1] Avenging Executioner - Complete Scoundrel: Many cool class features that scream this er is evil.

[2] Battle Trickster - Complete Scoundrel: If you can find at least 4 skill tricks you like enough, can be a decent 3 lvl Prc. I'd check out Group Fake-out, Timely Misdirection, Mosquito's Bite and Spot the weak point

[3] Dread Commando - Heroes of Battle: Allows for melee characters who wears medium or heavy armor to participate in stealthy antics.

[4] Disciple of Baalzebul - Book of Vile Darkness: More rogue than warror, but contains a plethora deception bases class features. You'll need to work with the DM to rework the fluff though.

Deceptive Feats (pathfinder only) you may wish to look at: Fox Style, Incite Paranoia, Wave Strike, Disengaging Feint, Disengaging Flourish, Disengaging Shot, Improved Dirty Trick, Greater Dirty Trick, Master Dirty Trick, Quick Dirty Trick, But a Scratch, Misdirection Tactics, Sliding Dash, Deceptive Exchange, Blustering Bluff, Feign Curse and Lifeless Gaze

Master Spy prestige class in Pathfinder is hard to beat, with its not-too-shabby d8 hit dice, and would complement a fighter very well (ftr gives you fort saves, this will give you ref and will). Take the Lore Warden fighter archetype for the 4+Int skill points per level and you won't have trouble meeting the prereqs: (don't worry about these not being class skills for fighters because upon taking the first level of Master Spy 'boom' they'll become class skills and you'll get the +3 bonus for each of these skills... )

Requirements
Feats: Deceitful, Iron Will.
Skills: Bluff 7 ranks, Disguise 7 ranks, Perception 5 ranks, Sense Motive 5 ranks.

....so you'd be looking at Ftr7(lore warden)/Master Spy X