Authority Clash occurs on a set schedule where the members of the Order and Chaos get together to fight for the pride of their faction.
House Feud is just like any clan battles that occurs between the guilds. It can may occur and end when the masters of two houses agree on it.
Territorial War refers to the conquering of the region by the players on the NPC controlled regions. The battle will be similar to that of the tournament between the houses, and the winner will take the rights of ruling the region as well as the tax rights along with unique house costumes for their members.
The castle siege has its purpose in owning the house or family that appeared in the actual comic book. It may only occur when your house owns the region near the target house. The first castle siege will be held with absence of the lordship, so the NPC will be guarding the castle. The winner of the castle siege will have the rights of taxing the nearby regions and they will be granted with house uniforms and special castle skills.
Unification is there to let users have the chance to unify the faction and be leaders of the faction that they represent. Only the houses that owns the castle may enter the unification battle. Unification is like a mission for the house, or its alliances. For example, as for the Chaos, their mission will be to take over the Palace of the Darksky Lord and his followers, the Blackwinds.