Unlike the other gods you cannot pray to Valpurus until you become his Champion, otherwise He will become angry and smite you in the head with his hammer. To become his champion you must pray to gods of similar alignment (Legifer and Atavus), or make offerings at his altars, or read his books (or a combination of these activities. To find out if you are ready to pray Valpurus just make a small offering at his alter (such as a lantern) and if he greets you as a "Champion of the cause" then you are ready. Your reward for devoting yourself to the King of Gods - either a valpurium two-handed sword or a valpurium shield. Sadly you do not get to choose. Once you become his champion you cannot pray to him again for 4 days with annoying him and 50 hours nd before you pray you must become a champion again. Then you can have a nice matching glowing green valpurium sword and shield(or maybe two swords or two shields).