It would be wise to bring a second signet capture because there's another monk boss (Scar Eater) between the armory and Jayne Forestlight
This boss is a very competent AoE Smiter using Zealot's Fire with high levels of Protection Prayers and Smiting Prayers. Be careful that your warriors do not die as they are next to him.
Approaching him from the west allows the Wardens around him to be more easily pulled away, in turn making him a much easier boss.
The name of this boss appears to be a reference to the character Jayne Cobb from the television series Firefly: One of the weapons he drops, "Vera", is the name of the character's favourite gun and the boss's Air of Enchantment elite was originally named Serenity, the name of the ship in the series.