9. 80s Colossus
Designed by Dave Cockrum for the All-New, All-Different X-Men during the 1970s, Colossus was the X-Men's first Russian member. Having grown up in a farm, Piotr Rasputin would leave his country to join Charles Xavier and his X-Men as the then youngest addition of the team. His first costume, consisting of red and yellow colours, was too similar to Nightcrawler's, though Colossus retained this costume initially. But as the new decade arrived, Piotr underwent a few costume changes.
While he sported an all red costume as his second uniform after the departure of John Byrne, Colossus would spend most of his time in the '80s sporting a shirtless appearance especially during the Outback era of the X-Men, where the team had relocated to Australia. It was a fitting change for Rasputin, allowing him to showcase his muscular physique and emphasized his status has the big, metallic man of the team.
The shirtless look would remain a defining staple of the character, with it being used as his reintroduction in Astonishing X-Men as well as his cameo during the mansion attack in 2003's X2: X-Men United.