I think storm deals with sentinel better than most of the cast can. Of course, it all comes down to how the sentinel plays.
I’ll share a little bit of what I’ve been doing against various sentinels (good and bad). Please keep in mind that good sentinels will use range attacks to create a good opening to rush down once they see how you destroy their ranged game.
Against the sentinel spamming mouth beams or drone projectiles:
If you do a neutral, normal-height jump you will be right above incoming mouth beams and in the perfect position to do a heavy whirlwind which will stuff almost anything sentinel can do with exception to hyper sentinel force (but that’s what you’re going to try and condition them to do). Against most sentinels just jumping and spamming whirlwind will be enough to frustrate them into attempting to rush you down, some will be capable enough to fight on par with you full screen (fortunately for us these better players are easier to condition). From full screen you want to try and bait a hyper sentinel force, or any projectile preferably when the opponent’s assist is not on on the screen and use storm’s level 1 full screen cinematic hyper. It’s the shoryuken motion + 2 attacks and hold heavy. This hyper will beat any projectile he can do, and makes you safe from hyper sentinel force as well. On top of that you can DHC it to anything at almost anytime if you need to. If you do accidentally catch sentinel’s assist a large ice block will be stuck on the screen preventing sentinel from using projectiles against you, including hyper sentinel force. The same large ice block will result from a rare trade with mouth beam, but it lasts a shorter amount of time. DO NOT USE VERTICAL TYPHOON TO ZONE, it’s an unnecessary break in your pressure for low reward for the risk. Also note that it is preferable to have one assist that fills in the gap for across the screen whirlwind pressure, and another assist that will create some pressure for a sentinel that’s found an opening and is trying to fly in for a frying pan combo (so any vertical assist, though some are better than others).
Against the rushdown sentinel:
At some point sentinel will try to rush you down, and while storm is very capable of keeping the bucket of bolts away, it’s very likely he’ll make it in at some point. When sentinel gets in you have to learn your opponent’s patterns to plan a counter attack. The most common pattern is from the air sentinel will frying pan, then crouching medium, then launch in attempt to catch you in some super/hyper armor. When fighting against sentinel’s rushdown, the trickiest thing to watch out for are assists that hit high or low because sentinel’s own high-low game is trash. If you want, you can block high and, on reaction, jump over his crouching medium and do a whirlwind to push sentinel all the way back across the screen, back into your ranged game. Or, you can block low and when sentinel jumps/flies to hit high you can attempt an air throw (which is a bit more risky if you don’t know the opponent’s patterns well) that can be followed up by an OTG vertical typhoon into various followups. Never try to throw sentinel on the ground–due to messed up hitboxes, unless you do a wave dash in storm can not throw a crouching sentinel and has trouble throwing a standing one doing attacks. Besides, there’s a good chance you’ll eat a launcher into a 100% combo. If sentinel doesn’t have a high/low assist the only ways they can touch you are chip from assist, chip from rocket punch, extremely risky chip from a ranged attack, his throw, or most likely his command throw which goes into a full combo. To deal with the command throw, always push block sentinel when he attacks to make sure he’s not right on you. When sentinel flies in–no problem. When sentinel wave dashes in they’ll likely try to use a command throw, or a crouching medium which which will both whiff against your up + back jump then you can punish. Watch out for assists when he’s doing this. If the wave dashing in sentinel does anything else, just be patient, you won’t eat much chip damage and if you ever start to eat a lot of chip damage from that scenario then you’ll have likely figured out his pattern.
Above all else, play defensively. You’ll gain nothing by trying to rush down sentinel and eating a foot to the face. If you do choose to rush down sentinel, make sure you have an assist you can get a combo from after you dash over sentinel’s head. Never go straight in unless you’ve practiced storm to the bone and know some sort of frame trap to deal with sentinel’s delayed super/hyper armor. I’ve had some good results from using the instant overhead exchange (jump, immediately float cancel, S) but sometimes I also eat super armor and die so I would not recommend trying it. Lightning attack can be used to go over sentinel’s head so he’ll block an assist the wrong way so you’ll get a combo from it. If you wish to fight sentinel on even footing, it just becomes a game of baiting his launcher. Learn his absurd range better than he knows it so you can cancel forward dashes into back dashes (baiting the launch) then dash back in for a full combo.
Just remember this: Fighting sentinel is lot like fighting a boss in Megaman games. If you don’t recognize the patterns, you’re going to get shat on. But as soon as you see the patterns, it’s manageable. When you’ve become accustomed to the patterns, it’s easy.