Oh dear god no, I'm not even to the second island's first trial on this file. I don't think I can check IVs until after the E4.
I just might go kill stuff with it. Will have to be careful not to replace the movelist though, it's very unusual.
Its moveset is set up to synergise with Mega Blastoise's ability; Mega Launcher (also held by Clawitzer, whose signature ability it used to be). Mega Launcher powers up aura and pulse moves by 50%.
Currently, all moves that work with mega launcher are identifiable by their Japanese names, which contain "hadou" (like hadouken). These moves are:
Aura Sphere (Fighting type, power 80, special, cannot miss) - japanese name "Hadouden" ("Wave motion Bomb / Surge Bomb")
Dark Pulse (Dark type, power 80, special, can cause flinching, 100% accuracy) - Japanese name "Aku no Hadou" (Evil wave motion / Evil Surge)
Dragon Pulse (Dragon type, power 85, special, 100% accuracy) - Japanese name "Ryuu no Hadou" (Dragon wave motion / Dragon Surge)
Heal Pulse (Psychic type, Heals 50% of target's HP, status, cannot miss.) - Japanese name "Iyashi no Hadou" (Healing wave motion / Healing Surge). It heals 75% instead if powered up by Mega Launcher. Only Clawitzer can utilise Heal Pulse and Mega Launcher.
Origin Pulse (Water type, power 110, special, 85% accuracy (primal kyogre's signature move)) - Japanese name "Kongen no Hadou" (Original wave motion/ Origin Surge). No pokemon can have Mega Launcher and Origin Pulse. That said, it can still be powered up by Mega Launcher.
Water Pulse (Water type, power 60, special, 100% accuracy, 20% confusion chance) - Japanese name "Mizu no Hadou" (Water wave motion / Water surge).
Of these, Mega Blastoise can utilise all but Heal Pulse and Origin Pulse. It also has 135 special attack, which is considered "quite good", better than Clawitzer's 120, and vastly more bulk and higher speed to boot. It's great at breaking through walls and stalls, but it struggles against Blissey and Florges, who are too specially defensive for even a powered up Dark Pulse or Aura Sphere to break through.
It's a fantastic pokemon, really. For most battles, I'd say your Squirtle would become your trump card by the time you get access to Blastoisinite (I think that's immediately pre- E4? By the time you've cleared the Poni Gauntlet which is mid 50s in levels).
Anyway, yeah, I generally don't bother with going for perfect accuracy when breeding pokemon. If a passive pokemon like Umbreon doesn't have attack IVs or spatk IVs i'm not really worried by that, similarly if a glass cannon seems to have tiny defenses then i don't really mind, as it's already glassy. Wonder Trade gets me enough perfects to start producing 5IVs or 4IVs en masse, and that's good enough for all but the top of all players.
@ Sirus: You can check IVs after hatching 20 eggs and speaking to a guy who sits at the Battle tree, just after the Poni Gauntlet. It isn't likely unless you go straight hardcore into breeding and upgrading your Isles to hatch eggs passively that you'll have that before the Elite 4.