Time to revitalize this. I'd make a long rant but I'll shave out all the fluff that would've been in it.
People complaining about having to stay indoors because going out is illegal.
"I have fully recovered from the C word so its safe for me to go outside unprotected"
Please, that doesn't mean that you'll get your body compromised once again. They even decide to protest overt his. You think that your personal enjoyment and thought of others' enjoyment of being able to go outside and enjoy large social group activities while an international crisis is going on because its not fatal to you? That overall sounds a lot selfish on its own and those types of actions are whats spreading it to the people that cant handle this type of nonsense and wouldnt be enforced even strongly if people would just listen for once.
Yeash, reading through the early to mid comments of this thread nearly gave me a migraine...course I find you here @Misty Fly
But still, the picture does not appear to be showing.
Lets see...So far you're self insert OC seems to be a changeling who used to be a normal pony that was beaten to death by a bunch of "evil" changlings (which I assume the time period would be pre season 6. Or if otherwise is part of the group of changelings that decided to currently follow Chrysalis after season 6 happens or if not were just ones going rogue). However, through a miracle he was somehow resurrected/reanimated in a zombie like fashion by something unknown which I'll refer to as a plot device. This side effect of said zombie in the form of a changeling lacks any form of feeling and was blessed with new powers which is to travel between dimension or moreso the real world and the gaming dimension and bring anything that occurs into video games into the real world. Also has access to electric magic.
All biases to species aside after seeing your original bio I suppose it is a step up and more detailed in comparison. Judging from those powers this would put your "demi" changeling to a minor illusionist or reality warper. Seeing how you say whenever he gets mad his power over electricity sky rockets at the point of causing a power outage which would have to happen via overloading and given how you say his weakness would be water it would make sense considering how electronics dont mix well with water. That I like how at least compared to other alicorn OCs that I've seen or witnessed you at least have a logical weakness for the character given their overall powers instead of making them absolutely broken for no reason even the princesses themselves who are viewed as physical Gods struggle against other beings.
Cons As much information you have there are several holes in the story that need more context or explanation to them. For example, what reason would the group of Changelings to attack Master Masher instead of removing him from sight. And also, there really no explanation to what actually gave him such super ponylike powers upon coming back to the land of the living. In a realistic sense someone would have had to have a hand or "Divine Intervention" to have that scenario play out. Finally there is no information about who he was prior to his (in tv tropes logic) moment "From Nobody to Nightmare" scenario.
What I'd recommend in improving the character in general is perhaps finding a reason for how he managed to survive and gain these new powers over resurrection. I noticed that in your first bio Masher was very attached to gaming that he dedicates his life to it. Even non unicorns have access to a type of magic even though unicorns are more adept at it on average. Also, unless the pony is the baby of alicorns breeding, alicorn by birth is impossible so perhaps you could make it so that his talent in gaming is what came into play when he gains those powers assuming that he was a unicorn back then or perhaps even before hand his that talent is what granted him his cutie mark and therefore seeing how that the only thing he felt it mutates into a central part of his magic. Do not be discouraged from having involvement with main or minor characters from the show as long as it is done right and not in a sense that your involvement is completely spotlight taking. Heck some people's ocs from this forum have their involvements with official characters but are treated as minor characters if such scenario played out from the shows or main characters perspective if it wasnt it's own canon though i myself all my ocs' settings take place in the official shows canon world(most of their bios taking place during s2-s3) though only involvement they have with any official character is through responding to the premiere or finale level of events since those were international level threats that you just cant ignore or at least try to stand clear of it if you were there in Equestria if it happen. I repeat there needs to be a reason for why those group of changelings attacked Masher. Even for villains they dont just do things because they're evil they have a goal in mind and in the changelings case assuming that they went rogue or work for Chrysalis they would have had to have been ordered to do so or were stationed to keep out intruders and attack on sight. Now back to my first statement which i hope that you will think over when improving this character, how did Masher come back to life? Again in your first short sentenced bio Masher had some involvement with Princess Luna with her watching over him. It is canon that Luna watches over the ponies in Equestria daily(no pun intended) especially at night in their dreams. Perhaps she had a hand in this scenario that led to Masher being who he is or another mysterious pony/creature that happens to be necromancer? Or perhaps Masher being taking the form of a "Super" Changeling is not but a side effect of being reincarnated in the world after from said necromancy. Finally, another possible scenario is that after said attack he was just mortally wounded and Princess Luna(or whichever character that had a hand in the transformation) decided this gift of power would be the only way to save him.
Now that I've said my piece I wish that you think on this if you want to make your oc more tolerable seeing as im noticing a lack of other ponies even being useful in giving advice.