Actually I think White Smoke would be an interesting choice, just to leave options other than the obvious Illuminate. Best sums up the typing and it's a nice irony versus the usual octopus/squid using black ink. Also I can imagine the false face appearing within the white smoke to be an interesting image as well. Also it can go with those underwater volcanoes and emphasise the Volcano part of its name.
On that note, Magma Armour and Heatproof are also good options as well. I don't think Volkraken is fiery enough for Flame Body so if you wawnt another heat-bases ability I'm up for this.
Other options could be Limber for flexible body, Pressure for living in deep, high pressure environments (going along with how Wailord can have it) and Unnerve for using it's false face to make prey nervous (similar to how Arbok has it).
On that note, Magma Armour and Heatproof are also good options as well. I don't think Volkraken is fiery enough for Flame Body so if you wawnt another heat-bases ability I'm up for this.
Other options could be Limber for flexible body, Pressure for living in deep, high pressure environments (going along with how Wailord can have it) and Unnerve for using it's false face to make prey nervous (similar to how Arbok has it).