1 - Return of the King (Arthas comes back but still as a villain)
2 - Pirate Arthas (Arthas joins Duke Falrevere's Bloodsail Pirate army and unites the biggest pirate fleet the world has ever seen)
3 - Frozen Tides (Arthas allies with Queen Azshara, N'Zoth and the Naga and they spawn more sea-zombie monsters in order to assault the cities)
4 - Arthas in the Jungle (Arthas travels to Zandalar and works under Rastakhan in order to boost the Zandalari Troll empire to rule again)
5 - A Song of Ice and Fire (Arthas and Sargeras team up as a Duo with frostfire demon zombies and try to destroy the planet all together
6 - Enter the Void (The Void Lords make Arthas their primary leader by infusing him with the central source of the Void and he becomes the ultimate villain of the Warcraft universe and the final war takes place)