Regarding "Blue Refess files..."
Before Set 9, Deep Ones were not viable for play and you could only build a Mermaid file. Looking at Mermaid skills, it's pure offense. Essentially, the tribe was a Blue Gowen file and still is today.
When the new Deep Ones came out, the file evolved into an engage control Blue file.
Sheacs, Lost One, Love, Mermaid Sorc. errata made open engage SP free, along with L1 Mermaid errata added another engage skill. I've even splashed Hunter Rosa into the file. Her huge boobs rival sea cow boobs.
It's possible to put your opponent into an engage lock and standby every turn while Ebreenu buffs Deep One's HP until your units are too strong to overpower. This is made easier with the new Ex Boobs which can cover your units from attack.
There you have a Deep Ones control file. It's kind of like Refess, but focused more around Falkow mechanics and tricks like moving engaged units to other slots, and of course return, so I would still call it Blue Falkow file.
There is a problem that prevents this kind of strategy from being really good, instead of average. Because you have no control over most Deep Ones skills, it often forces you to attack, thus giving your opponent a chance to counter, rather than being able to just pressing "standby" until your field is unbeatable like most control files are.