The Anime Lad
Varvatos is the most powerful being of his age and finds the position unbearably dull. He reincarnates as Ard after calibrating his magic to be perfectly average. The modern world has become much weaker than expected. His carefully ordinary power is therefore exceptional again. Historical benchmarking has failed him.
Super Eyepatch Fox
Ultimate power becomes boring. Varvatos chooses reincarnation and sets his future magic at the old world's average. He returns as Ard in a far weaker age. The calculation produces another overwhelmingly powerful life instead of the typical one he requested. His careful reset has recreated the original inconvenience.
Gigguku
Varvatos tries to escape overwhelming power by doing the math himself. Average magic, ordinary rebirth, problem solved. Except the modern world is so much weaker that Ard comes back overpowered anyway. I love a premise where the grand reincarnation scheme fails because the benchmark went stale!
Father's Basement
An overpowered reincarnated lead is hardly fresh. The only useful wrinkle is that Ard attempted to prevent the outcome. Varvatos deliberately selected average magical strength before rebirth, then discovered that the modern world had declined far below his reference point. The same old power fantasy now begins with a failed calculation instead of pure luck.