When talking to and teasing Sentry, it normally uses human form. Sentry became a respected superhero by civilians and other heroes, and is considered one of the most powerful beings in Marvel and its universe.

In March 1947, Canada's Department K and remnants of the United States Operation: Rebirth pooled their resources to become Project: Sentry, an attempt to not only recreate the Super Soldier Serum, but in post-war hubris, magnify its effects a thousand times over. Sentry is a superhero in the Marvel Universe and also carries within him the supervillain known as the Void. Incredible Intellect: Sentry is not only shown to have god-like physique, he also has shown to be …

Unfortunately, within a thirty years it had been divided nearly a thousandfold into isolated sub-projects, with lab work farmed out to private contractors. Mastermind, hired by the General, had used the great mental powers the Sentry needed to contain his abilities to force everyone (himself included) to forget of the Sentry's existence. The … With this new found knowledge, the Void disappeared, and Emma Frost resurrected the Sentry.

Realizing that his archenemy the Void is returning, Reynolds seeks out several prominent Marvel characters to warn them and to discover why no one remembers the Sentry. The overall admin… The Void is the black and destructive counterforce and negative aspects of arguably the most powerful of all heroes, the Sentry.

Middle aged, overweight Bob Reynolds remembers that he is the Sentry, a superhero whose "power of one million exploding suns" derives from a special serum. After gaining his powers, the Sentry would become a part of the superhero community of the early Marvel Universe, making friends with the Fantastic Four, the Avengers, Spider-Man, and the X-Men. It is more of a force than a person but can take any shape it chooses. Originally a meth addict, Reynolds consumed the Golden Sentry Serum, a serum to replicate and be better than the Super Soldier Serum, and gained superhuman powers.

The experimental serum creates a phase-shift in his molecules, causing the Sentry to become partially out of synch with normal reality. The Sentry's superhuman powers and abilities derive from a special version of the Super-Soldier Serum of which it's potency was increased thousands of times and altered making it much more potent. Should the Sentry ever remember his life, then he would be struck by a fear of the devil attacking the world, hence the Void. It is capable of destroying the Earth, if not the entire universe.

Strangely enough, his golden aura had a soothing effect on the bestial Hulk of the day and the two would work together. Since he can control matter to a… The Sentry (real name Robert "Bob" Reynolds) is a superhero in Marvel Comics.