Missing 3 achievements

Hi, does anyone know how to unlock these 3 achievements? They are the last ones I'm missing. I would be very grateful for help and tips. If anyone needs help with any other achievement, write and I will try to help.☺️

Who am I? (Discover the secret of the Tidewalkers)

Armistice (Reunite Omulus and Raymus)

Cooperation is key (Make everyone collaborate for the world's destiny)