Lucius Sergius Catilina, a Roman politician who prepared a rebellion against the Senate. The object of many famous Cicero speeches. The gens Sergia was one of the oldest Roman families, it existed in the time of the kings.
The Russian saint Sergiy Radonezhskiy was named "Sergiy", not "Sergius". "Sergiy" is still used in Ukraine, but you do not even have this name on your list.