The thread will be divided into a few sections to showcase the various aspects of Havok. Unlike some posters I prefer to let the scans do the talking, and as such I include only a minimum of description with each picture, hoping that the context will speak for itself.
I – Power
II – Heat
III – Absorption
IV – Durability
V – Leadership
VI – Versatility/Other skills
VII – Fights
Havok, also known as Alex Summers, is the son of Christopher Summers and Katherine Anne. He is the brother of Cyclops and Vulcan. Uncle to Cable and somewhat related to the gazillion Summers' children running about the Multiverse. He is also the father of Katie Van Dyne Summers, who is also lost in the Multiverse.
Havok has the power to absorb ambient cosmic energy and release it in the form of cosmic energy blasts. These blasts superheat things, cause them to explode or knock them over. While he generally has an “average level” he can also actively absorb energy and go far beyond. He has traditionally struggled with maintaining control over his powers and has at various points in his history resorted to wearing energy-regulating suits, similar to Cyclops' visor.
He had a history of living in his brother's shadow, being seen a lesser leader and such, but started stepping out of that shadow with X-Factor and has in recent years reached heights far above anything Cyclops has ever accomplished. Not just in more or less single-handedly rescuing the Universe/Multiverse, but also in becoming a more accomplished leader and staying true to Xavier's dream.
Havok has recently been leading the new Avengers squad, but seems to have broken apart to join his brother due to the personality shifts in Axis. He has also been banging the Wasp.
Havok must have some kind of superhuman durability, some of the stuff he survives is just so far beyond what any human could ever hope to live through. Yes, this part is essentially Havok getting beat on. (please log in to view the image)
V - Leadership
Finally there is the oft-underrated aspect of Havok, his leadership. As of now he has lead the Two instances of the X-Men , Fallen Five, The Dark Descendants, Two instances of the Avengers, The Starjammers, X-Factor. This section will just include a few examples of him acting as the leader of these.
VI – Versatility/Other
This section will be a bit of a repeat, as it showcases the various things he can do with his seemingly one-sided abilities, examples of control and other skills.