I'm going to be running my first game with some friends in a little while, and we've all decided to start at the Submerged power level.  There will be four PCs, and they haven't rolled yet, but I doubt any would play pure mortals.  The guide says that equal opposition would be equivalent to the total refresh of the party, but I statted out the shapeshifter below (apologies if the format is not what is typical, I'm new) and it looks as if they would not be able to take this enemy in a fight.  Does this look like something 4 PC's at the submerged power level could take on in a fair fight, or is this a more challenging encounter they'd need to research and significantly prepare for?

Skills default to Good (costs 75)

Fantastic: Might, Conviction, Fists, Discipline, Lore (15)
Superb: Presence, Stealth, Intimidation, Deceit, Endurance (10)
Great: Alertness, Athletics, Survival, Investigation, Burglary (5)

True Shapeshifting (-4)
Modular abilities (-16)
Evocation (-3)
Thaumaturgy (-3)
The Sight (-1)
Soulgaze (-0)
Lawbreaker First Law (-2)
Lawbreaker Second Law (-2)
Lawbreaker Sixth (-1)

Mythic Toughness (-6)
Catch (0, party/story dependent - likely native american rituals or something, as long as it can tie into plot well)
Refinements (-4) (+1 power, control Spirit) (+1 power, control air)(ability to cast final two elements, each at plus 1 power)

Base Stress Tracks:
Physical OOOO(Toughness OOOOOO)(OO) (Armor:3)
Mental OOOO(OO)
Social OOOO(OO)

Tank form (giant lobster with translucent shell)
Physical Immunity (-8) (catch boiling water +2)
Mythic recovery (-6)
Hulking Size (-2) (Physical stress track is OO longer)
Recover from stress as if consequences are 3 steps lower, shake off 3 minor consequences as sup acts per fight. 

Grappling form (Dire Wolf)
Mythic strength (-6) (+6 damage to fists) (grappling benefits)
Poisoned claws (-3)
Supernatural Speed (-4)

Flying form (jet black bat)
Mythic speed (-6)
Poisoned claws (-3)
Flying (-1)
Supernatural Strength (-4)