There's a good reason Viltrumites don't use cybernetic parts: this.◊ You're welcome.
Allen gets horribly wounded and hospitalized by a pair of Viltrumites. But it turns out that his powers work on the premise that whatever doesn't kill him makes him stronger... much stronger. The next Viltrumite to attack him received a very, very unpleasant surprise.
Angstrom Levy get a villainous one in Issue #60, Invincible War, attacking the planet with a small army of Alternate Universe Invincibles. Just about every superhero on the planet has to contribute in order to save the world from utter destruction.
Also from Invincible War, Rex Splode's Heroic Sacrifice. The only thing getting in the way of the badassery that is charging his own skeleton to explode when finally out of options is the fact that this long lasting (if unpopular in-universe) character is the fact that it happens so hastily and doen't hold much impact due to the 'Event Comic In One Issue' nature of the book.
A somewhat minor one for the author Kirkman. After the Viltrumite War, Mark return home to find that Eve has gained a significant bit of weight since he left. Mark clearly doesn't mind at all, and while she does seem to drop a few pounds later on, the weight gain itself is not treated like a problem. Kudos to Kirkman for trying something so few comics would.
The series in general has made quite an impact at Image, with various spin-offs and a much brighter tone than the infamous Nineties Anti-Hero days, while still keeping excellent storytelling and the frequent gruesome imagery.