I don't know Sentry, however, if you do there are a couple of things to consider when dealing with any "Storm vs." discussion. Take this as food for thought and then come to your own conclusion since you likely know Sentry much better than I do.
1) She's Mistress of the Elements and her mastery extends to controlling the elements within people'se bodies. This is one hard power to fight. We have seen her control the air in people's lungs and the pressure within people's bodies. She has destroyed a Herald of Galactus with her control over electrons and controlled people like Hydroman. She controls moisture, Hydroman is composed of water thus he fell under her dominion. If Sentry or anybody has forces present in their bodies that falls under Storm's dominion and if these things being in tact have a direct impact on their survival or remaning conscious, then she has an advantage over them unless they have the power to dispute her dominion over said forces. Keep in mind that Storm has power to rival the Phoenix. If any of you are new here and don't know it yet, I can do a post on this. She's like an elemental equivilent to the Phoenix. This is a woman who was able to go to the Trion dimension and wrest control of the elements from them. The Trion are the sum of an entire reality and were the "gods" of that reality. They were the forces that composed that dimension given form. So exctly who is going to wrest control over the elements from this woman? Nobody that I can think of.
2) Storm has a tremendous attack speed. She has a unity with life itself and her power flows from this connection. Read this scan:
http://img212.imageshack.us/img212/6445/stormandthegalaticcore15zq.jpgHer powers are limited by the force of her will and strength of her body and are linked to her emotions. Hence, she has been able to attack with
less than a conscious thought on panel. This makes it nearly impossible to speed blitz her. Say you have a character who can move faster than thought or attack faster than thought (well, I guess Storm can fall in the latter category, lol), they can have a problem against Storm since she can command nature with less than a conscious thought and nature carries out her will before her conscious mind can even catch up with what has transpired.
http://img46.imageshack.us/img46/2803/lessthanacnsciousthoughfo4.jpgSo a writer can have Storm beat pretty much whomever they need her to beat.
3) What I am about to post about Storm vs. telekinetics can be applied to many other characters with similar type powers as well.
Against a telekinetic, Storm's best defense may be a strong offense. She could strain a telekinetic out by assaulting them with elemental assaults that force them to continually put all of their concentration into maintaining a shield until pass out from the strain. One advantage Storm has with her powers is once she sets up an attack, she doesn't have to concentrate to keep it going. Nature will do that for her. Hence, in some cases, she's whipped up hurricanes in fights and was knocked out. The hurricane still raged on until it ran out of energy on its own. So Storm can create an instant storm against a telekinetic. The TK now has to create a force field and anchor themselves against her attack (keep in mind that due to the inherent nature of Storm's powers, her attacks are continual. A hurricane, for instance, does not let up, but strikes continually). So while th TK is doing this and getting tired, Storm is not expending any energy for the storm to keep going as nature continues her attack for her. She can then fly around and use her hand lightning and direct the winds to hammer the field with all objects in the area to add to the stress until the TK passes out.
I can produce scans of her stressing out Jean Grey's TK in such a manner without even trying.
Well, I'll just do a scan now:
http://img362.imageshack.us/img362/2700/hruncanny20xmen2032020lsw8.jpgStorm's target was Legion, not Jean Grey as they were on the same team. Jean was only getting a taste of what Storm was dishing out against Legion and look how it taxed Jean Grey. Storm's attack was so ferocious that she broke the rules of nature.
4) Then we have the brute force Storm can dish out. Remember how I talked about Sienna Blaze?
http://img361.imageshack.us/img361/797/xmenunlimited0114oe7.jpghttp://img361.imageshack.us/img361/763/xmenunlimited0141wh5.jpghttp://img361.imageshack.us/img361/1756/xmenunlimited0142fb5.jpgNote that Sienna's blast are said to be similar to the power of the Phoenix.
Circa Excalibur issue 72 or73, Sienna Blaze casually tossed a blast at Nightcralwer that had enough power to fry him to a crisp, sink Muir Island and half of Scotland Mainland. In the issue where she battled Storm, Sienna Blaze has enough power to split the planet like a ripe melon. Xavier telepathically forced Sienna to unleash all of the power she had to temporarily burn her out. He succeeded as she admitted this. Furthermore, she could barely speak or stand. Storm summoned an electrically-charged wind tunnel to redirect Sienna's full power when she did that blast that burned out Sienna's powers. The issue stated that Scott just sat there and blasted in case any of Sienna's energy got away from Storm's vortex.
There are TONS more scans of Storm doing impressive feats of raw power as you all know. She's summoned the full power of a galactic core which included the power of millions of stars, she's wielded the power of the solar wind and she controlled the elements globally to create a weather shield around the planet to deflect a planet-destroying blast from the sun. The sun's resources are greater than that of a planet's, so she amped up the power of her shield by pulling gamma rays out of a gamma ray gun and fused it with the energies of her elemental shield (just goes to show how much energy she can wield), she defeated the Trion, she controlled a hemisphere-sized hurricane and channeled a continent-sized blizzard through her body. She has winds strong enough to level mountains, strain Magneto's powers to the utmost and scour she surface of the world to its bedrock (however, the winds she would have had to use to redirect Sienna Blaze's full power like that would actually dwarf these wind feats, but they are still impressive and worth mentioning). She completely destroyed a herald of Galactus (who was able to reconstitute himself/herself after she destroyed him/her- I am unfamiliar with Stardust's gender) and the list goes on.
5) Storm is innately attuned to her environment. She can feel movement in her environment (heck, she was in Africa and was able to "feel" Cyclops moving through the air in the Blackbird over the United States and literally blasted him out of the sky with a lightning bolt while half a world away). She can detect energy, shifts in energy fields, she can detect the life force in all living things and can perceive the world as patterns of energy and forces that she can bend to her will. This also allows her to see through matter. For instance, she has been able to see through walls with this ability as well as cast her vision over an entire continent. I have scans for all of this if anyone doubts it. So really sneaking up on her is impossible if the writer uses this aspect of her powers.
6) The lady has an indomitable will. Her powers are limited by the force of her will and strength of her body. She has proven to have the will to best psis like Xavier, Shadow King and Bogan even when the power of other psis are added to one of these. To boot, the electrical energy in her nervous system affords an extra measure of protection against invading telepaths. She has displayed the ability to amp up this electrical power in her body to literally fry an invading telepath out of her mind with a massive feedback. Its the equiviland of the psi grabbing ahold of a lightning bolt!
ouch! Eternity is essentially the sum of everything and Storm had the strength of spirit to house his essence in his body. This is a feat that would have killed others including the Silver Surfer as stated in the issue. So telepaths are out.
7) If Storm is up against a techno opponent like Iron Man or Ultron, she can get an real easy win here. Iron Man's suit requires power to run, power that Storm controls. With just a thought, Storm can make that power go away just like she did to a Skrull space ship in the scan below:
http://img71.imageshack.us/img71/5516/emdownpf3.jpgActually, in Iron Man's case, since he's still human, she can go at him other ways too. She could, for instance, command the air in his lungs and beat him that way.
There are still more nuances to Storm's powerset, however, as you can see Storm has a very potent arsenal and skill set that's very, very hard to beat.
This is just food for thought when you're thinking about Storm vs. anybody.
