The outcome of a hypothetical battle between Thor, Doctor Strange, and the Avengers joining forces to confront a demonized Loki, who is darkened by the Void, would depend on several factors, including the specific powers and abilities each character possesses, the circumstances of the battle, and the specific interpretation of these characters within the storyline. However, I can provide an analysis based on their typical abilities and characteristics as depicted in various Marvel stories.

1. Thor: As the God of Thunder, Thor possesses incredible strength, durability, and the ability to control lightning. He wields the enchanted hammer Mjolnir, which grants him flight and the power to channel his lightning-based attacks. Thor’s combat skills and his connection to Asgardian magic would make him a formidable opponent.

2. Doctor Strange: Doctor Strange is the Sorcerer Supreme, possessing vast magical abilities and knowledge. He can manipulate reality, teleport, create energy shields, and cast powerful spells. Strange’s expertise in mystical arts and his ability to tap into different dimensions would provide him with a wide range of options and strategies in battle.

3. The Avengers: The Avengers are a diverse group of superheroes, each with their unique abilities. The specific members involved in the battle would determine the strength and capabilities of the Avengers in this scenario. They could include characters like Iron Man, Captain America, Black Widow, Hulk, and others, each contributing their respective skills and powers to the fight.

4. Demon Loki: If Loki has been darkened by the Void, it would imply that he has been corrupted and enhanced by formidable dark powers. Loki is already a master of deception, manipulation, and sorcery. With the added dark enhancements, he would likely possess increased strength, dark magic, and possibly other abilities granted by the Void.

Considering these factors, the battle would be intense and challenging for both sides. Thor’s raw power and lightning attacks would be effective against Loki’s darkened form. Doctor Strange’s mastery of magic and ability to manipulate reality could provide crucial support and strategic advantages. The Avengers’ combined strength, skills, and teamwork would further add to their effectiveness.

Ultimately, the outcome would depend on the specific circumstances, the level of power and control Loki possesses over the Void, and the tactical decisions made by each side. It is difficult to determine a definitive winner without more information about the specific scenario and the plot details of the story.