Jamie Alexander (Sif) had a particularly bad injury while filming in September.
“It was raining, it was dark outside, it was like 5 in the morning — and I went down a metal staircase and slipped and slipped a disc in my thoracic spine and chipped 11 of my vertebrae. I knocked my left shoulder out of place and tore my rhomboid on my right side . . . It took me out of filming for a month. I heal really fast. Everyone thinks it’s really funny to tease me about staircases now that I fell down one . . . I’m walking in heels again though, so that’s a good sign.”
Malekith's MCU design differs significantly from his comic book look. Instead of the "80s glam rocker" look of the comics, Malekith has pale white shriveled skin; half of his face is badly burned/scarred; he wears dark armor and black robes; and wears a long platinum-blonde ponytail braid. Also, there appear to be CGI contacts located around his brows; purpose unknown.
The Dark Elves under Malekith's command wear dark armor and black robes, and appear to carry hi-tech beam weapons. Their faces are covered by unsettling metal face masks, and it is unknown if their facial/racial features are the same as Malekith's.
The battle filmed at Bourne Woods features Asgardians (in golden armor very similar to Heimdall's) battling what has been called "Marauders." The design for the "Marauders" does not show a monolithic army belonging to any one race, but many different races, both human and non-human. The Marauders display weapons from various tech levels, ranging from swords and spears and axes to high-tech beam weapons. Some of the Marauders even seem to come from different cultural backgrounds, and are seen in the gear of samurai, Chinese warriors, Middle Eastern warriors, and European warriors of the Middle Ages and ancient times. Generally, the Marauders seem to be "color coded" to a red-brown color for their armor and weaponry, although not all wear that color.