>>545000320
Yes, a Mary Sue means a self-insert girl that often gets romanced by all the men, and either has mysterious special snowflake powers or is a weak damsel in distress, depending on what the fanfic author prefers. Think of Bella from Twilight, she's the quintessential Mary Sue.
If you think just being really strong makes one a Mary Sue/Gary Stu then you're retarded and don't know hat you're talking about.
>>545000494
He's just a deity. Is it a crime for a dragon god to be strong?
Gary Stus are a bit more vague because the term Mary Sue comes from fanfics written by women, but technically harem protags with special powers are Gary Stus. Caelus is a bit like one.