The real regulus problem.
Sniper scope.
Wut? A regulus can take an tower down in a minute, without losing hp or being even remotely is danger. Combined with mines, you can down the entire left lane in cataract before lvl 6.
Sure, you can chase him away, but he'll just come back or wait for his friend. A good Regulus will mine every passage towards him so no teleganking or something. Also, he can support his teammates with snipe too, while attacking a tower and waiting for a new creepwave.
He isn't really losing anything from standing there since the towers are ussualy in the way of creepwaves.
He is not supposed to be the best siegeDG.