Adam Cain A-218 is the Commanding General of the UOGE, Ace of Blades leader, and (after the Battle for Nirn) Jarl of Ace City. His military accomplishments are many. Being UOGE and therefore not native to Nirn, he is usually considered to be similar to a Nord or Imperial but is thought by some to be closer to the Altmer (mainly due to skin color) in genes and magic prowess. He gives quests for the Battle for Nirn quest arc and the Ace of Blades arc afterwards. During the tropics mod (in alpha), he is encountered in new armor slaughtering a group of Revolutionaries.
The Ace of Blades normally wields his two famous daggers in combat, the Ace of Blades Dagger and the Cybertanium Dagger, as well as knowing many three word Thu'ums and knowing many spells. He is usually suited up in the Ace of Blades armor, his own Heavy armor set. When encountered as a Void Walker, he wears the Ace of Blades' Void Walker Armor, a light armor set with various enchantments. As a Void Walker, he fights with the Ace of Blades' Void Walker Swords and the Ace of Blades' Void Walkers Bow which he uses to fire Void Walkers arrows. He usually poisons these weapons with poison against his target's highest value (if the target has the more magicka than health or stamina, he will use a magicka poison, etc.). When seen acting as the Jarl of Ace City, he wears a unique version of the Dragonplate armor, but without a headpiece. With all of these he wears the Cain Family Ring and the Lord's Amulet. When seen during the final battle of the main quest in the Tropics, he is in the Ace of Blades' Shark tooth armor with a Sharktooth amulet on. He wields the Ace of Blades' Sharktooth Daggers here and uses his Ace of Blades' Sharktooth Bow to fire Shark tooth arrows when spells and Thu'ums are out of range.
During the Battle for Nirn, he gives you quests and he gives you the quests for becoming the Thane of Ace City, the Ace of Blades missions, and the Undercover questline which you can do to slowly get your bounties cleared thanks to A-218 pulling a few strings. He'll also occasionally give you the location of a dragon and a bounty letter for it. He will sometimes be seen with a unique brown dog. Talking to him while the dog is near allows the dragonborn to ask about the canine. The resulting dialogue opens a quest in which you retrieve several artifacts for him. Once completed, the dog, named Daisy, will be available as a follower. She is skilled in combat, can uniquely carry items (up to 150 units) and evenually gives you a quest (in her own doggish way) that allows you to give her a powerful unique armor set. He occasionally asks for random items (commonly amythest) in misc. quests. Completing so many of these will give the Dovahkiin unique rewards, like teaching him how to make a new kind of jewelry or an how to smelt certain items together to make a different item (like a recipe for Daedric Orichalcum.)