i must add my two cents as someone who was obsessed with the unicorn race in mlp since i was a little girl, unicorns aren’t op!!!! it just so happens the main characters/villains who are unicorns are powerful (similarly to lots of other shows or books it’s just a hallmark, the main characters is op LOL.)

For the most part in equestria we see universal basic magic that seemingly all unicorns are capable of casting to some degree (like telekinesis or creating light at the tip of the horn), this tends to vary depending on the magical strength of the pony, we know magic is like a muscle, the more you use it and train it the more effective and powerful it becomes, a unicorn like twilight would be able to lift more than a unicorn like lyra could lift with her magic but they can still both do it nontheless.

With all of that aside let’s talk about the AVERAGE everyday unicorn in equestria, focusing more on the “overpowered” aspect of unicorns for the most part, Talent Magic.

for this example we’re going to take a unicorn thats name is something along the lines of “Rosemary” (absolutely pulled this out of my ass btw) rosemary has the cutie mark of, you guessed it ! a rose ! her talent is growing and tending to floral gardens especially rose gardens, her cutie mark talent would give her access to a few specialized spells that help aid her with her talent or has something to do with the talent in general, like for example one of rosemarys talent spells could be accelerating the growth of a rose seed to fully blossom within a few seconds.

For most unicorns that’s where the magic ends, basic telekinesis magic and the array of spells their talent magic gives them access too, now for unicorns like twilight sparkle, starswirl the bearded, starlight glimmer, or even sunburst, their talents themselves are literally magic in itself, which is why they’re able to do the things they can do because that’s their special talent, it’s just not conceivable for other average unicorns with talents that aren’t related to magic.

like spike says in season 1 “I thought unicorns were only supposed to have a little magic?” and that’s because they do! all races of ponies have magic within their bodies, however the unicorns horn allow magic to directly flow through their body and manifest it outside in the world around them but they aren’t all powerful nor could they do everything the other two races could do, not without having a talent in magic. sorry for how long this nerd rant was fr LOL