I've ran several variations of a Curve Sentinel deck since early December so I figured I could be of some help here.
First off, the deck looks pretty good to be honest. Although I do have a few fixes.
Rather then run the Wild Sentinels as another 1 drop, run Sentinel Mark II as a 3 drop. Right now from what you've got, you're working with no 3 drop, and the point in a Curve Sentinel deck is to actually hit a drop on every turn that is equal to the turn number you're on (so Boliver on 1, Hounds of Ahab/Mark III on 2, Mark II on 3, Mark V on 4, Nimrod on 5, Master Mold/Bastion on 6, Magneto/Tri-Sentinel on 7).
Running multiple 1 drops isn't going to help in this deck, in fact, the 1 drop is probably the one turn that doesn't really matter in any deck, it's the turns after that that really matter, so having a 3 drop will definitely help. So add some Mark II's.
Next up is the Magneto that you're running... I'm not too sure what the point for it is. Most Curve Sent. decks run Magneto based on the fact that they run Genosha along with it and draw 4 cards per Genosha on turn 7 after dropping Magneto, MoM. My advice would be to go one way or the other, either run 3 Tri-Sentinel's or run 3 Magneto's (with Genosha's), I'll touch on this more later.
As far as plot twists go, you run the average plot twists for a Curve Sent. deck. Umm... I'd run 4 Savage Beatdowns instead of 3, but I'm guessing you're just short 1 Beatdown (which isn't bad). You could however sub in a Mega-Blast or maybe a Flying Kick if anything in place of it, Mega-Blast's tend to be a nice addition though in some Curve Sent decks (especially since many of your characters will eventually hit the Support Row).
I'd also suggest maybe running at least 1 more Overload. Running just 2 seems a little short handed on their point. You want to combo off Overload with Nasty Surprise against your opponent's characters every now and then, and really having at least 1 more will just help give you that edge in accomplishing that combo.
Prime Sentinels... hm... To be honest, I looked at this card just recently and thought about maybe running it, but to be honest, I don't see it covering the major goal of a Curve Sent. deck and therefore could be just in the way of other possible cards. Youc an remove these 4 cards and add in like 1 more South American Sentinel Base and then 3 Underground Sentinel Bases... or 4 Genoshas... whichever you want to do.
South American Sentinel Base: Hmm... Well, Running this doesn't hurt so much, but helps in the end most likely, but I was gonna say take these out for Genoshas... but after reviewing Prime Sentinels, I'll leave that as the possible take out. But this will seem pointless after that when you're drawing at least 4 cards on turn 7 anyways (granted that's if you actually draw Magneto and a Genosha during the game).
But that's if you want to run Magneto, if you run the Tri's, go the other route, it's up to you.
But other then that, the deck you posted I'd give overall a 7/10, it's good, but could be improved. Let me know if the fixes work or not.
