Return of Nightmares
My idea is this. After Azeroth hero's have defeated Deathwing, Thrall with his friend started fixing azeroth. While they were returning Azeroth to normal something strange happend. One person visited Icecrown Citadel. At the top he put something strange into a corpse. The corpse was Arthas Menethil's . After that he visited Black Temple too resurcting Illidan Stormrage. Now Bolvar Fordragon is dead and Arthas made his retun as The Lich King. But that is not only thing. Illidan Stormrage made his return too, and he will revenge to everybody who tried to kill him. The new/old Lich KingArthas and Illidan Stormrage are working together. Building the army of the Scourge and Demons are up to the revenge. But that isn't only bad thing. Sindragosa is back to serve Arthas once again. What will happen next? To start revenge Arthas killed Tirion Fordring. Oh yes by the way. Arthas re-forged pices of Frostmourne once again to blade.
New things in game: Level cap raised to 90
New class change: "Death Knight class will now serve to [[Lich King]. When they finish starting quests for talent points and other, they go to leveling. When they reach level 90 they can go in icecrown to Shadow valut which is now their city. Main objective of Death Knight is to go and kill both ally and horde players
Some kind Of PvP arenas with more demolisher and destructable buildings
Talent system would be same like in Cataclysm
New raids First i would like to add: Cosmos's hold: 10/25 man raid: It would have like 15 bosses and last one Cosmos, Human Death-Knight who resurected [arthas] and Illidan Stormrage.
Dark wings lair: 10/25 man raid: Dark wings would be a faction which is fightning for Illidan's forces, main goal of them is to make Azeroth defense destroyed so Illidan can get azeroth to himself.
Many new quests
Some new zones