critique wanted I feel both my OCs are Gary Sues

[Will Guide 21,360]

I wrote this before on the topic: Mary Sue and Why We Hate Them, but I feel I could get more advice here:

To be honest, one of the reasons I never got around to fully writing any potential fan fiction is because I'm afraid I made my OC Ponysona, Will Guide too much of a Gary Sue. I mean, being able to use Pixie Dust from the World of Disney to temporarily fly seems a bit OP. Plus although I use the Beast's Magic Mirror so that both Will Guides can talk to the others. (One Will physically outside the mirror, the other whose face appears inside the mirror), I'm tempted to have it break the story and spy on the villians right away. I try to handwave why I couldn't just use my abilities to solve all the episodes' conflicts so quickly by saying I'm magically restrained from using my Disney Magic to its full potential since it comes from another world and so its function work differently. But I don't know; it sounds like a lame excuse when I say it like that. 

As for Character Flaws, well, Changeling Will Guide starts off feeling he needs me as Unicorn Will Guide to even exist, but learns to stand more on his own. To the point, we could part ways for a while without him feeling too insecure. Also, there's a part of Changeling Will Guide that wants Chrysalis to accept him, but she never did and never will.

As for myself as Unicorn Will Guide, I feel there's not much change to my character after my "big intro episode". I remain more or less the same person. The only big things I've done since then is successfully get Spike's Egg from his doomed parents to Celestia during the S5 finale Time-Traveling Trip and rediscover my Changeling Soulmate. I would spend parts of the rest of the show after Season 6 as a Big Brother Mentor to C. Will. Other than all that, I feel Unicorn Will Guide is just me making wish fulfillment.

So in short, I'm not sure if my OCs avoid falling in the Mary Sue Traps. Other than me, who would want to read about my characters' experiences in Equestria and maybe even the Equestria Girls World? Maybe even C. Will's experience in our reality if I decided to go that far?

[Misty Shadow 7,846]

Personally, I feel what's more important than stressing over your characters being too powerful is ensuring that the story shows how they've earned their powers. As long as the conflict of your story is interesting and gives the characters the pruning they need, you'll be fine. 

[Ittoni 538]

well, if you have seen that your character has no flaws and can't fail but i think that it definitely does and their story should be working to solve them.

About the magical abilities, yeah you will have to make a pretty good reason of why should they have them in the first place and if it's worth having them. Wouldn't it be better to instead of having the magical magoffins, have the thing that disney character excel at? which is the magic of love, friendship, compassion, etc.  everything else that is an artifact or magic helps too but the core of the characters and movies goes beyond a magical solution and that could be your own character's strength more than the abilities themselves. instead of phonecalling the plot character of the week from the magic mirror to solve a problem why not actually go there with them and have a nice one on one chat, because is nicer than sending them a phone apology, or don't spy on the villains because that's bad and a true good character wouldn't do that, it's invasion of privacy even if it's the bad guy's house. You will have to do it the good guy's way, which is usually not the easiest. Or put some limits to the magic of the mirror itself. make the others realize that spying on others is bad so your character has a flaw they will have to work on to get better.

about the changelling situation, yeah, from my own personal opinion i would say that they are in a pretty bad codependent relationship if he can't exist or be without the other, either physically like with Will or emotionally with Chrysalis. is not healthy. they will have to come to terms with each other if that is causing them distress and you will have to find a solution to it. does he feel ok with it? and if not then what can you do about it? will it be good for them to say he is fine even if he depends on others? because once the others are not there for him he won't be able to sustain himself and that's why these kind of situations are bad even if right now he doesn't have that problem.