Marvel's Avengers campaign missions are usually packed with combat sequences, with a few puzzles on occasion. However, the game is essentially a loot-focused game, so players need to collect a few items here and there during campaign missions.
One of the campaign missions that players need to collect loot for is the Starktech Outfits mission. To complete the mission, you must collect Energy Boosters from Fallen Prime Synthoids, Fallen Riotbot Optical Decoders, and Fallen Synthoid Memory Chips. While the latter two are fairly easy to find, finding Prime Synthoids is a bit tricky as they aren't as common as Riotbots and Synthoids.
There are two missions where Prime Synthoids spawn. The first is Captain America's iconic mission, Red Glare of the Rockets. The mission is in the Utah badlands and you can follow Captain America's iconic mission from the menu to highlight it on the war table. Most often, doing this mission once should get you all you need for the Starktech Outfits mission. However, sometimes you may not be able to get the Prime Synthoids from this mission.
If you are unable to get Prime Synthoids in the Rockets' Red Glare mission, you must research the Communication Nexus Sabotage Drop Zone mission. Prime Synthoids are very common in this mission, so you will definitely find them here. Keep in mind that this mission is on rotation, so you might not have it right on your war table. Try going to Ant Hill and also check the War Table if it doesn't appear on the Quinjet. If you want to know how to get the rest of the gear for the Starktech Outfits mission, check out our guide here.