The effect of "Deep Sea Diva" can be used to Special Summon "Neptabyss, the Atlantean Prince". Then, its effect can be used to search an "Atlantean" monster, by sending "Atlantean Dragoons" from the Deck to the Graveyard, which in turn will search any Sea Serpent monster. After that, this card can be Synchro Summoned and used alongside with one of the searched monsters to Synchro Summon another monster.
"Atlantean Dragoons" can be used to search "Moulinglacia the Elemental Lord", whose Summoning condition will be fulfilled after this card have been used to Synchro Summon a monster.
While the condition of "Fishborg Launcher" only lets it be used for a Synchro Summon of a WATER monster, it can be used to Synchro Summon this card instead, which can be used for any Synchro Monster.
This card can be used to Synchro Summon "Yazi, Evil of the Yang Zing". If it's destroyed, its effect can be used to Special Summon "Magma Dragon", whose effect can be used to Special Summon this card, setting up another Synchro Summon.