Captain America & Thor: Avengers!

Captain America & Thor: Avengers! is a comic book set in the Marvel Cinematic Universe.

Plot
When HYDRA's U-Boats take out an Allied target, it's up to Captain America and his Howling Commandos to strike back! The heroes sneak into a HYDRA U-Base, but there they find that the tentacles in the HYDRA logo might not be simply symbolic!

Characters

 * Captain America
 * Dum Dum Dugan
 * Jim Morita
 * James Montgomery Falsworth
 * Gabe Jones
 * Jacques Dernier

Locations

 * Gibraltar (mentioned only)
 * Gibraltar (mentioned only)

Items

 * Captain America's Shield
 * Captain America's Uniform

Vehicles

 * Leviathan

Organizations

 * Howling Commandos
 * HYDRA

Plot
When Fandral - one of the Warriors Three - is taken captive, it's up to Thor, Sif and Loki to get him back... despite going up against one of the fiercest creatures in the Nine Realms!

Characters

 * Thor
 * Sif
 * Loki
 * Fandral
 * Hogun
 * Volstagg
 * Heimdall
 * Alflyse
 * Kurse
 * Malekith

Locations

 * Svartalfheim

Organizations

 * Warriors Three
 * Dark Elves

Non-Canon Character Bios
Citadel of Spires provided backstories for Malekith and Kurse that are not compatable with the canon of Thor: The Dark World and the Marvel Cinematic Universe.

Malekith
"Well, Malekith...nice to meet you. Prepare to die." "My sentiments...exactly."

- Loki and Malekith

Malekith was the royal mage of Alflyse, the Dark Elf Queen of Svartalfheim. He was at the Citadel of Spires when the Dark Elves captured Fandral, an Asgardian who was sent by Odin to spy the Dark Elves.

When Fandral's friends Thor, Hogun, Volstagg, Sif, and Loki came to free Fandral, Malekith surprised Loki and Sif who were trying to sneak into the Citadel. Malekith and Loki fought a magical duel, but Malekith soon proved to be a better sorcerer than the god of mischief himself. Their battle ended in the Citadel's courtyard where Thor summoned a lightning which burned Malekith.

Kurse
When Fandral was captured by the Dark Elves, Loki, Sif, Hogun, Volstagg, and Thor snuck into Svartalfheim, the realm of the Dark Elves to save him. As the team split up, Thor, Volstagg, and Hogun were ambushed by Algrim, also known as "Kurse", one of the greatest warriors of Svartalfheim.

During the battle, Sif found Fandral, who was actually enjoying the intimate company of Queen Alflyse, while Loki fought against her royal mage Malekith. In the Citadel's courtyard, Thor used his hammer, Mjølnir, to defeat Malekith. Then, while Loki distracted Algrim, Thor destroyed the tower and defeated all of the Dark Elves.

Trivia

 * The section of the comic titled Citadel of Spires has been deemed non-canon due to its multiple contradictions to the events of Thor: The Dark World. So far the U-Base section of the comic is still considerd canon since it has there has not been any events in it that have contradicted an event in any of the films.