One of the coolest twists on Spider-Man was when he was merged with the elusive and sentient energy known as the Enigma Force, or sometimes the Uni-Power. It seems to appear whenever it chooses, usually temporarily bonding with someone in a dire situation, turning them into Captain Universe. It can join with anyone, from a regular human, to the Silver Surfer, to the Hulk, and once even a dog. Once joined, the person’s appearance changes into something resembling the Captain Universe costume, and they gain cosmic levels of power. Powers include flight, matter and energy manipulation, enhanced knowledge known as the Uni-Sight, and enhanced strength. The stronger the host is, the stronger the gained strength increase seems to be.
Honestly, the Uni-Power is one of the most random things in the Marvel Universe. In the early days, it always seemed like a weird lab accident seemed to summon it to whoever was in the accident, but later that was changed or made to be just a coincidence that it had happened to all the previous hosts. Later it just showed up and powered people up. When Spider-Man got it after a lab accident, he initially believed his new powers to be a further evolution of his spider powers, but after some time he suddenly realized it was the Enigma Force, and that something in the lab accident had just slowed the merging process so he got the powers but not the knowledge of what was going on. After he defeated the Tri-Sentinel, the power left him, leaving him as regular Spider-Man once again.
In a “What If…” story, after defeating the Tri-Sentinel, the Uni-Power stayed in him. His overwhelming sense of responsibility that came with the overwhelming power drove him to easily defeat all his regular villains, and even try to change the world’s climate so arid areas such as Africa became bountiful. He became a target by more powerful villains, and in trying to defeat them, Cosmic Spider-Man allowed hostages to die. Peter realized the Enigma Force was taking control of him, and allowing a few to die in the name of the many. Peter then took steps to remove the Uni-Power from himself, dispersing it over the globe.
In yet another instance, we saw in Spider-Verse that there was a Peter from Earth-13 who still kept the power, and stayed as Captain Universe permanently. He describes his powers as those of a god, but that they will only work in his universe so he can’t travel between worlds with the various other Spider-Men and Women to stop the Inheritors. Unfortunately when the battle comes to his world, the leader of the Inheritors, Solus, is able to defeat and kill him by draining him of his life force.
Positively Jim 