THE DESTROYER, otherwise known... as eric.

[u/EntertainerPure8440]

Lord Voldemort - Tom

Mister Incredible - Bob

The Son Of God - Yeshua

Basically, really intimidating nicknames used instead of birthnames, the likes of which aren't intimidating at all.

Title taken from this video (timestamped).

• LORD VOLDEMORT (Harry Potter): otherwise known as Tom.
• MISTER INCREDIBLE (The Incredibles): otherwise known as Bob. My man was genuinely named Robert Regular lmao
• THE SON OF GOD (New Testament): otherwise known as Yeshua, an extremely common name back then.

[u/kaimcdragonfist]

In a world of names like Cloud, Aerith, Genesis, Angeal, Rude, and others…

Zack.

[u/Old-Sacks → u/kaimcdragonfist]

Stranger of Paradise takes this to the extreme with its protagonist Jack.

[u/Andrew1990M → u/Old-Sacks]

I think Final Fantasy XVI tops this with Mythos, Shield of the Phoenix. 

AKA Clive