I'll concede that yes, the 'B Team' has a great amount of hype surrounding them, but none of them are 'jobbers'.
Mirajane - the 'Demon' - If she had more of her original personality, I bet that Mira would be twice as badass as she has appeared until now. That and her stronger set of moves were essentially 'sealed away' for 3 years, so yes, of course she'll be rusty in using them once more. She will ALWAYS be the girl who fought Titania to a standstill. Apparently, Satan Soul uses up a ton of her magic to make the transformation and unlock her stronger moveset so I look for her having increased her magic endurance and possibly some other Take Overs as well. She's also skilled at Transformation magic so changing into someone else just to screw with them is possible as well...
Laxus - Arguably the strongest mage in Fairy Tail behind Makarov and Gildartz, if he still has his dragon laychrma, well, we know that anyone facing him is going to be in for a 'shocker'. This guy is smart, has a keen grasp on what his magic can do and be utilized for, and his base stats are higher than anyone elses. And his jerkass fascade only helps him because he
will ram a lightning bolt through you to hit the guy behind you if he has to - he'll just make it pass through you so that you don't die.
Gajeel - As much as we made fun of him for being the Ace of Phantom Lord and to be owned by Natsu, of all people, he is still a Dragon Slayer and a force to be reckoned with. I'll even give him some more heat and say that he's probably the weakest in B Team. But compared to A Team who has Lucy as their weakest...I'd take Gajeel personally. Also, between him and Laxus...railgun anyone? 0-0
Juvia - the water woman who
SCARED Erza...
Depending on Gray's proximity, she can be potentially jobby or scarily competent. We know that water is extremely powerful and like Natsu-tachi, she went through Ultear's little Time Arc method so she might be a lil unstable coming out of the starting block.
and 'Mystogun'...
Can he even duplicate Mystogun's illusionary magics? As soon as he uses his 'Heavenly' magic, the gig is up. Might be interesting to see. ...damn it, why did Mystogun have to have JELLAL'S face...why not Simon or just...someone bloody ELSE... ><