User blog comment:Ash9876/Standard Magic and Lost Magic. Pros and Cons/@comment-27047411-20200214233953

I believe some of the cons are kinda subjective and are not even weaknesses. Like being a outcast, sadly none of the slayers in canon are even outcasts, so idk why that's a con. You should be able to do a lot with Slayer Magic, the only difference is you'll be immune to that element.. and you can eat it, besides that it's normal magic.

Totomaru can only manipulate fire, so only Fire-based slayer magic will have trouble. Physical conditioning is yet not really a con, but a general weakness all mages has (also depends how you use the slayer art). When you run out of magical power, everyone's useless.

Meaning, at least half of the cons are conditional and not truly weakness.