Hyper Combat Unit Dangaioh(1987)

Haja Taisei Dangaiou

When four psychic warriors discover that evil invaders have destroyed their planets, they are brought together by a mysterious doctor to unite to form Dangaioh, the most powerful weapon in the universe. Using their full collective cyonic powers, they alone can stop the bloody tyranny of Captain Garimoth and his wicked henchman to prevent the end of the universe.

(Source: Manga Entertainment)