Note: This blog was made in place of DerDoppelganger and is copied from their comment on the Hestia Familia page
We've discussed who would next join Hestia Familia on many occasions, but since it might be someone yet unknown, the real question is: What are Hestia Familia's needs?
Bell is a well-balanced speedster with a no-chant magic, who can occupy almost any position in a formation, although he is best suited for the middleguard, since he can move at will between positions. This has affected his status growth, with him having to more or less act as a babysitter for not only Lili and Haruhime, but Welf and Mikoto as well.
Welf has more than decent destructive power, but relatively low defense and only short-range / melee attacks, leaving him in charge of the vanguard. That being said, his magic, Will-o-Wisp, can be used from any position and over long distances, although it has limited applications.
Mikoto is another well balanced adventurer, with short, middle and long-range attacks, not to mention her martial arts proficiency and gravity magic, with the latter better left as a last-resort. Her skills would make her a formidable scout, but she is rather relegated to the rearguard, which is understandable, since monsters can appear out of nowhere after being born from the Dungeon.
Some say that Lili and Haruhime are barely worth mentioning, but the former is not only a supporter, but a fine tactician with long-range attacks as well. As for Haruhime, her only redeeming quality is her magic, Uchidenokozuchi, which after being cast, leaves her as nothing more than a burden (and eye candy).
With that in mind, Hestia Familia's needs are obvious: a healer, a mage and a tank.
There is nothing that a healer can do that potions, antidotes and elixirs can't, especially since they now have a steady supply of dual potions thanks to Naaza. Of course. It is always better to have a healer in a party, especially one on Fels' level, but if Hestia Familia could only acquire one new member, I would choose someone else, since they can always go on joint-expeditions with Miach Familia, now that Cassandra has joined them.
As for a mage, it would mostly be for offensive purposes, although there is not much that can resist an overlimit Argonaut-powered Firebolt. Still, it's area of effect is limited, which will be a problem when they have to face hordes of monsters in the deeper floors of the Dungeon, but they still have a way to go before then. It would also be useful in the case of monsters who possess high defense or are even resistant to physical attacks, but not enough to justify the need for a mage.
In my opinion, a tank would be the best addition to Hestia Familia, since it would free Bell from having to defend his relatively powerless teammates, who are the main reason why they are still stuck in the middle floors of the Dungeon. Even though the Goliath Robe can protect Lili and Haruhime from physical and magical attacks, it does nothing against the subsequent shockwaves, as is the case with helmets and sub-concussive brain damage. The typical dwarf with a shield would do the job, especially since he wouldn't be a threat to Bell's harem.
That being said, I am still rooting for Ryuu to join Hestia Familia, for previously stated reasons, but honestly, do we need a reason for wanting to see more of her?