The Power Stone is one of six Infinity Stones, and so frequently it tends to be considered part of a matched set. While that sometimes isn't wrong (such as when it is fused to the Infinity Gauntlet), it isn't entirely correct either.
The Power Stone is its own entity, with rules and abilities unique only to that one particular stone. As such, there's a lot to learn about it. Who knows, this information may one day save the Marvel universe. Or create a much bigger problem.
10 Arguably The Biggest Mystery Of Them All
While there is still a lot to learn about all of the Infinity Stones, there's no doubt that fans know more about a few of the other stones than the Power Stone. This is a stone shrouded in mystery, with the upper limits of it being left unexplored – and that's a good thing.
The only history there is to know about the Power Stone has been supplied by directly witnessing where it has been and how it was used. For example, all of the times Thanos tried to get his hands on it.
9 First Appearance
The Power Stone was first considered a Soul Gem – as in part of a collected set. It had no distinction beyond that. None of the stones did. It wasn't until the Stranger (actual name) found them that the stones each got their individual identities.
It was actually the Power Stone that the Stranger first got his hands on, and which started the entire quest to compile them all as a complete set. Fans surely know exactly how bad that journey has gone (for any character that makes the attempt).
8 Manipulates All Forms Of Energy
At its core, the Power stone grants the ability to manipulate any and all energies. It is capable of massive creative feats, as well as devastating moments of destruction. What does it mean, to manipulate energy? Well, it means that theoretically anything one wants to do with energy – of any form, be it magic, electricity, light, etc – can be done. The limiter is the control and creativity of the wielder.
7 Increases Effects Of The Other Infinity Stones
One of the key features of the Power Stone is that it enhances the other Infinity Stones. One can theoretically hold the other five and have great power, but they would need to get their hands on the Power Stone in order to stand any chance at controlling them all.
That is why the Power Stone is consistently the stone of honor, so to speak. It gets a special place on the Infinity Gauntlet, for example.
6 Omnipotence
The Power Stone is able to enhance the user beyond the obvious as well. It can grant physical strength and other enhancements known to superheroes – and more. It can also grant the wielder a sense of omnipotence.
Granted, that one can only occur at the stone's full potential, which is far from easy to achieve. That is probably for the best, given how powerful and destructive this stone can be.
5 Stability
The Power Stone is required as part of the Infinity Stones set for many reasons. One is that it enhances the rest, as mentioned above. It also stabilizes the set. Theoretically, if one were to bring the other five together, they would be in for a world of trouble, as the stones are too unstable like that. But throwing in the Power Stone would change everything.
4 Changing of Hands (MCU)
The Power Stone has changed hands a few times, even just in terms of the MCU (which has a much shorter history than the comics). First, it was shown hidden away on the planet Morag. That's where Starlord found it, and how it eventually ended up in the hands of the Guardians of the Galaxy.
Next, it wound up in the hands of Ronan the Accuser, who tried to use it to destroy Xandar. Perhaps it is only natural then, that it ended up in the care of Xandar. Ultimately though, Thanos got his hands on the stone.
3 Accidentally Swallowed
Following the events of Infinity Watch, the Power Stone, as well as the rest of the Infinity Stones, were separated and given to those that were most trustworthy of caring for them. The Power Stone ended up in the hands of Drax the Destroyer.
At this point in time, Drax was going through several changes and was not exactly himself. That's why he mistook the Power Stone for a jelly bean...and swallowed it. On the bright side, that probably helped to hide it for a while.
2 Infinity Wars
Most recently, the Power Stone once again became involved in a war around the Infinity Stones – the Infinity Wars. Here many characters from the Marvel universe came together to prevent another Thanos-level event.
Their plans didn't succeed, as it was Gamora herself who used the stones to alter the universe of Earth 616. Following the events of the war, the Infinity Stones were granted a semblance of their own sentience, and thus able to decide their own destinies. For a time, at any rate.
1 In The Chest Of A Villain
So where is the Power Stone now? Most recently the Power Stone was shown to be residing in the chest of a villain, Star. She first came to life within Captain Marvel's series, but has since had her own miniseries.
While it's unclear where she'll appear next, it is obvious that both she and the stone will be making appearances in the greater Marvel universe.