What does Regis mean?
From Latin 'regis', the genitive of 'rex' — literally 'of the king', i.e. royal/kingly. Popularized partly via Saint Jean-Francois Regis. Means 'of/belonging to the king' rather than 'king' itself.
What does Florian mean?
From the Roman name Florianus, a derivative of Florus, from Latin 'flos/floris' (flower) and 'florere' (to flourish, bloom). Carried by Saint Florian.