The Ebonheart Pact is one of the three joinable factions participating in the Alliance War, the other two being the Daggerfall Covenant and the Aldmeri Dominion. The crest of the Ebonheart Pact is a dragon, and its colors are red and black. It consists of four of the five Dunmer Great Houses of Morrowind, the Nordic kingdom of Eastern Skyrim and the Argonian tribes of northern Black Marsh. The alliance was reluctantly formed out of necessity; despite the three races' ancestral hatred for each other, they recognized the threat posed by their unified enemies, both at home and from across the sea, and banded together to protect their borders and freedom. Led by Jorunn the Skald-King, who presides over the Great Moot in the Pact's capital of Mournhold, the alliance seeks to defeat the corrupt Empire and preserve the independence of its homelands. Pact players will begin on Bleakrock Isle after being washed up unconscious on the shores of the island following their escape from Molag Bal's realm of Coldharbour.
The Elite Guard are a group of three Dragonknights. They appear to be Empress Regent Clivia Tharn's Dragonguard, although they are seemingly unrelated to the true Dragonguard who await a Dragonborn to serve. They initially serve as companions during the quest Planemeld Obverse, but you will later have to fight them during the third boss encounter in White-Gold Tower.
The Erabenimsun Tribe is a tribe of Ashlanders living in Vvardenfell. Ashlander Tribes and Customs describes them as a war-loving tribe, heavily armed, and valuing strength above the lore and history that the other tribes value. The Erabenimsun notably were the first to tame wild nix-oxen.