|Priest of Balthazar|
Every skill, rune and upgrade is available from every Priest of Balthazar, except for those in the Ascalon Arena and the Shiverpeaks Arena. However you can easily get access to all upgrades by making a PvP character who can reach the Battle Isles. Note these upgrades are available only to PvP characters and heroes.
There is a Priest of Balthazar in every PvP outpost (except for Shing Jea Arena), at every Alliance Battle map, in every Guild Hall (if the guild has bought it from the Guild Lord), and on The Battle Isles. Some have names, others are simple labeled with a generic "Priest of Balthazar [Rewards]".