- Badass Decay: Like many comics strongmen, Colossus has a distressing tendency to be used for The Worf Effect. His appearance in X-Men is a good example.
- Escapist Character: Of an unusual sort in the superhero genre, as while many superheroes exist to serve as a power fantasy, Colossus's main purpose over the years has evolved into being a Romance fantasy. A Hunk with Chronic Hero Syndrome and Incorruptible Pure Pureness, Colossus could have stepped whole and breathing from the most wholesome books of the Romance Novel genre. Most of what he does and who he is is defined by his love relationships, another trademark of the romance novel love interest.
- Iron Woobie: Honestly, Piotr's life wasn't great shakes even before the '90s, but the Trauma Conga Line he endured then (that killed off both his parents as well as (temporarily) his brother and sister) was so... well, traumatic, that it's really amazing that he's held onto his Incorruptible Pure Pureness. Of course he didn't at the time — in fact, he hit a Despair Event Horizon and pulled a FaceHeel Turn — but he's since recovered his firm moral principles and remains one of the strongest candidates for The Paragon out of all the X-Men.
- Launcher of a Thousand Ships: Combined with his Flat Character, at times it feels like the sole reason Colossus is kept around is to be a Ship Magnet for other, more lively characters. He initially had a crush on Storm (as did almost everyone under Chris Claremont's pen), but it was his romance with Kitty Pryde that became his first true relationship, and to this day it is regarded as the One True Pairing of Colossus among X-Men fans. Undeterred, Ho Yay shippers delight in pairing him off Wolverine (with whom he is Heterosexual Life-Partners with), Exodus (who he followed during his brief FaceHeel Turn in the '90s) or Deadpool (mostly because of Deadpool (2016)). On the heterosexual end, he's paired with Callisto of the Morlocks, Meggan of Excalibur, and Domino of X-Force. Executive Meddling created a character just to be his love interest, but neither she nor the random Savage Land woman he had a child with (later established as not his) stuck in shipping circles like the above have.
- Memetic Mutation: His distinctive "WHOAAAAAARGH!" Battlecry from the 1992 X-Men arcade game.
- One True Pairing: As mentioned above, while he's shipped with many characters, his relationship with Kitty Pryde is regarded as the OTP by a large segment of fans, particularlly those fans who grew up reading Uncanny X-Men in the '80s.
- Strangled by the Red String: Piotr's twice been strangled by this. During the Secret Wars (1984) event, Executive Meddling on the part of Jim Shooter (who wasn't comfortable with the jailbaity aspects of 19-20 year old Colossus romancing a 14 year old Kitty) forced Colossus to fall into instant love with Zsaji, a character specifically created for the event. While Zsaji succeeded in putting off the Colossus/Kitty relationship until both characters were of age, it was not received well by fans and Zsaji has barely appeared since the '80s. In a more recent case, he sparked a relationship with Domino out of nowhere in the pages of X-Force (2013), noteworthy for splitting both characters off from their usual OTPs. This one was a little more popular, resulting in a Broken Base, but it didn't last long and Colossus soon returned to romancing Kitty... only to be left at the altar.
- Tear Jerker: His Trauma Conga Line back in the late '80s/early '90s was this, as Piotr lost literally his entire family due to one tragedy after another. Sadly, the impact of it is diluted to modern readers since his sister Illyana and brother Mikhail both came back to life later.
YMMV / Colossus