The Reaper Destroyer (Rannoch)
The Reaper Destroyer encounter on Rannoch is a multi-stage battle. Initially, you'll need to disable its weapon systems by targeting specific weak points with a targeting laser. This requires careful maneuvering to avoid its devastating attacks, including beam weapons and missile barrages. Once the primary weapons are down, you'll need to fight your way to its core, often involving clearing out Geth and Reaper forces. The final phase involves a direct assault on the Destroyer's exposed core. Utilize cover extensively, manage your squad's abilities, and focus fire on the core when it's vulnerable. Biotic and tech powers that can disrupt shields or armor will be particularly useful here.
Kalros, the Thresher Maw (Tuchanka)
Facing Kalros, the Thresher Maw, is less about direct combat and more about strategic guidance. Your objective is to lead Kalros to a specific location where it can destroy a Reaper blockade. This involves navigating through heavily defended areas while protecting Kalros from Reaper attacks. You'll need to clear out enemy emplacements and ground forces that threaten the massive creature. Use your squad's abilities to control the battlefield and create openings for Kalros to advance. Be aware of its powerful burrowing attacks and the debris it can kick up. The environment itself can be used to your advantage, with choke points and cover offering temporary respite.
The Collector Praetorian (Various Missions)
The Collector Praetorian is a formidable boss encountered in various missions, particularly those involving Cerberus or Collectors. These enemies are heavily armored and possess powerful biotic and ranged attacks. Their primary threat comes from their devastating energy blasts and their ability to deploy shields. The key to defeating a Praetorian is to target its exposed biotic nodes, which appear after it uses certain abilities. Use heavy weapons or concentrated fire from your squad to break through its defenses. Biotic powers that can lift or stagger it can create openings. Keep moving and utilize cover to avoid its most damaging attacks. Prioritize eliminating any smaller enemies that accompany it to maintain focus on the Praetorian.