disguising an Urgathoan cleric NPC as a cleric of Saranrae

[GM and the Holograms]

I'm hoping to find some suggestions for how I can hide my necromancer NPC as a cleric of Saranrae. I'm aware of undetectable alignment, which mechanically is probably all I need. However, I'm not aware of a way to make them detect as good. I'm hoping you all may have some suggestions for good flavorful options. The cleric will be level 5ish if it matters.

[blashimov]

While if you have undetectable alignment, it's no use detecting as good, but here's one way:
http://www.d20pfsrd.com/magic/all-spells/c/celestial-healing/

There are a very few class abilities, such as the master spy's, that allow one to fool divination magic, however you might be looking for misdirection: http://www.d20pfsrd.com/magic/all-spells/m/misdirection/

Should cover all your needs. (That and disguise + bluff of course.)

[Tarik Blackhands]

More so than auras you're going to run into issues with your unholy symbol if you want to do anything other than whack things.

Divine Focuses need to be presented clearly if you want to spell cast (or channel) and flounting around an Urg symbol or channeling negative energy in general is going to get you busted immediately even if you don't ping as evil. Sure in theory you can have a dozen holy symbols on your neck and hope no one notices, but that's still suspicious for an actual cleric, especially one diametrically opposed to your patron.

[Lanathar]

Perhaps an illusion could make the holy symbol look different
But clerics do not tend to get those kinds of spells

Not sure if disguising magic changes that either

[GM and the Holograms]

Misdirection looks like a good resource. Thanks.

As for the holy symbol issue, if they need the cleric to channel energy for them they're past the "investigation" phase of this scenario. So, I'd count that as an alternative means of outing the big bad.

[Renata Maclean]

An evil cleric also can't cast celestial healing, as it has the Good subtype

[tonyz]

This would work better for a cleric with the Trickery domain, methinks (bluff and disguise class skills, some illusion magic). Of course a hat of disguise might be helpful too.

[Daw]

Don't forget Sarenrae Temple-Lore and Knowledge Religion, and rather a whole lot of Bluff.

[Nathan Monson]

There is an archetype for exactly that. ill look it up and post back
I was thinking of the Hidden Priest Architype; which lets you pretend to be a non-Divine caster.my bad

[Mr. Bonkers]

To gain a Good Aura, look no further than the Deceiving armor quality. For 5000gp on top of a +1 magic armor, this enchantment makes sure that no matter what, you radiate a good aura and masks whatever aura you truly have (no influence on other things, like smite evil, just the aura).

As for the divine focus thing, you could consider a Recondite Holy Symbol. This represents a very old symbol of a faith, which requires a dc15 Religion check to identify. Regular citizens probably won't figure out it is not a Sarenrae symbol, as you need to be trained in religion for checks with a DC higher than 10. Most likely far easier for your players, but still useful for background reasons.

[GM and the Holograms]

Awesome, thanks for all the ideas everyone.