Hearthpwn

An idea of an Tempo Priest happened when Extra Arms was announced to be buffed. It wasn't good enough but maybe Blizzard thought it would be OP so they sent Mind Blast to Wild (we all know the Class identity here is pure BS).

Wretched Reclaimer also fits into Tempo Priest. With this you can target some cards that summon themselves when they die (Grandmummy, Recurring Villain, Zerek, Master Cloner), but you can also target some good deathrattles (Dead Ringer, EVIL Conscripter, Convincing Infiltrator). You can even target Zilliax for extra heal and board control.

I replaced Power Word: Shield with Embalming Ritual. I think Power Word: Shield is better than Embalming Ritual when you look across all priest decks and usages. But in this deck I think Embalming Ritual fits more. Giving Reborn to almost all minions here is going to be very useful. Best targets are Grandmummy, Recurring Villain, Zerek, Master Cloner (the best target in my opinion), Dead Ringer, EVIL Conscripter, Convincing Infiltrator, and  Zilliax.

Whatever you say, Psychopomp can be good in Tempo Priest. Even if you get an EVIL Conscripter its so good. The only ones you don't want to get is Madame Lazul, Wretched Reclaimer and maybe Grandmummy (since it already has Reborn). With everything else you get value for healing or deathrattles.

The Mulligan is simple, look out for these cards:

Northshire Cleric, Embalming Ritual, Dead Ringer, EVIL Conscripter, Extra Arms, Grandmummy (replacement for Mind Blast)

Against Aggro: Forbidden Words

Against Control: Vivid Nightmare, Zerek, Master Cloner

Why Zerek, Master Cloner againts Control? Because he is one of your Win conditions. Try to get him out in the early game when you can still have value of him and face your opponent.

Win Conditions: Convincing Infiltrator, Recurring Villain, Zerek, Master Cloner

Replacements:

Madame Lazul - She is used just as card knowledge, I would replace her with Omega Medic for late-game

Zilliax - he can be used for healing and control, he is pretty useful. But if you don't have him (it's almost an auto include in every deck you should craft it), I recommend putting Faceless Manipulator for more Win Condition copies.

I know about Activate the Obelisk, but I'm not quite sure how to put it in. Probably a better Deckbuilder than me is going to make that deck similar to this one. I really like Activate the Obelisk but I'm not sure which cards to replace for Quest support. If you have any ideas tell me in the comments below!

I'm not the best deckbuilder so if you have any replacements or corrections tell me in the comments below!