Leveling Up

So, this really does depend on what skill branch you went, but I'm going to start with Buff/Heal, since that's without doubt the most common for a BP.
Buff/Heal - So, you're job is really quite simple...you buff them when they ask you to, and if you're the only priest, give them some heals. Or you could do what I do, and claim to be Buff/Duff, so they get another priest and you just sit down and relax xD
Heal/Duff - This branch requires you to be on your toes. You gotta heal when someone starts dropping (pretty obvious) and if you let them down, it usually means the boot.
Duff/Heal - When I started a Duff/Heal BP, the only reason I was able to level, was because I had a clan that was leveling me like crazy. Even though that was happening, I still eventually went back to Buff/Heal to exp easier. Moral of the story, bad choice for exp.

PK'ing

Ok, so this is really the most important part, and the funnest part xD
Now keep in mind, I always PK as Duff/Heal, so all my advice is really regarding that type, since I hate being Buff or Heal during PK.
In order to do good, you're going to want the top end equipment mentioned earlier, uniques and DD being the most important. I woudln't really suggest getting your feet wet until level 57, because thats when, as a buffer, you get 1500 buff, and as a Duffer, you get Torment (AOE armor debuff). If you're the guy with just average equipment, then just hang back, and try to get a few kill steals xD But if you're buffed up, you wanna lead the pack. You run in there, find a party of two or three, and tear them apart. You will want to (as a duffer) Torment them all while your team runs ahead, then Parasite the strongest (Warrior > Sin > Priest > Archer > Mage) and take em all down a few NP.

Solo'ing
Although this really doesn't occur much in DCZ, you might run into one or two, or maybe you're in the arena.

Mage - Mages under 59 are USUALLY pretty easy for a BP, mainly because they're commonly loaded with Dagger Defense, which won't help them in this situation. Parasite is most important, Torment if you can get it off, then tear them apart. Once Parasiting, mages really aren't a problem.
Warrior - Usually the most difficult, the routine pretty much stays the same. Parasite, and you will DEFINATELY want to get off Torment vs. a Warrior, so Parasite, then Torment, then go after him with you're strongest skill, then you're spammable skill, throwing in your stronger attack whenever you can.
Priest - Again, duff, duff, duff. It really is the key to success. If you run into one of those bastardly Intel Priests who just spam heals himself, get your party to hop in, and gang bang the fucker
Sin - Duff. Once a sin is duffed, if he doesn't town like the pussy he is, he will get OWNED. End of story. Usually they Spike, then /town. Dinks.

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