The Metro Exodus Full Strength trophy is a long and difficult one to complete; the trophy is directly tied to attaining the game’s “good” ending, and requires you to keep the band of Spartans in one piece as you progress through the game. This is done in three specific ways. Firstly, you need to make sure that Duke doesn’t die in the Volga. Then, you need to ensure that Damir doesn’t leave the group in the Caspian. Now, you also need to see to it that Alyosha isn’t wounded in the Taiga.
Metro Exodus Full Strength Trophy: How to Stop Alyosha From Being Wounded
Just like the first two sections of the Metro Exodus Full Strength trophy, preventing Alyosha’s wound requires you not to hurt any of the Pioneers; the human locals inhabiting the Taiga. Just like with the cultists in the Volga and the slaves in the Caspian, you must avoid harming these individuals to get the trophy. Unaffiliated humans, like bandits, can be killed without risking the trophy. However, to avoid accidentally failing the trophy, the safest thing is to rely on stealth and nonlethal take-downs whenever you encounter any humans in the Taiga.
Note that you can actually complete the Forest Child trophy here at the same time; this trophy requires you to complete Taiga without hurting anybody and without ever being spotted. You can complete this trophy alongside Full Strength, as the objectives do align. However, note that Full Strength doesn’t require you to avoid detection or avoid harming anyone (just Pioneers). So, Forest Child does make things somewhat more difficult. However, completing it here could save you time in the long-run if you plan to complete it at some stage anyway.
Unlike the section of the trophy in the Caspian, there are no specific objectives in the Taiga. Simply play through the region without ever harming any of the Pioneers. At the end of the section, you and Alyosha will zip-line over to the Aurora. If you were successful, Alyosha will be uninjured and jump onto the train. If not, he will be wounded and will have to be helped onto the train. Now, if you have completed the previous two objectives concerning Duke and Damir, you will now get the Metro Exodus Full Strength trophy.