If you have servants to work for you, every day is quite relaxed, and you only need to check the arena's earnings once.
(There is no accurate information, but I think crossing over to become a member of the Ancient God Race has a relatively higher safety factor. Small-scale wars do not require your personal involvement, and having a large number of slaves that can fight on your behalf.)
Risk factor: 2 stars
Development speed: 8 stars
Development potential: theoretically infinite (though lower than the Horror Black Tide and Combat Insect Clan's clear infinity, it's just based on theory)
Option five: Soul Returning Clan.