its hard to tell if its a battle against mage and a level 5 because their hasn't been any real battles yet. But if aqua's magic is like the magic that instantly appears and not travel then it can just explode inside the fire wall of accel. But who know's.
But I'm still betting on aqua weilding ascalon. Its like aqua performing omnislash
As for mikoto..... well we haven't really seen her go out wild. The only thing I saw when she goes max firing electricity is against the baby and against touma. But touma wouln't even get damage from it and the baby artificial angel needs to be go against max if mikoto wants to live. She is fighting an artificial angel even if its still a new born baby. Other than that. If I take the battle of mikoto and mugino as an example but mikoto is completely exhausted already plus mugino is just playing around. So can't tell.
The only great fights are the fight of Accelerator. Maybe that's why his the main man for science side as for touma taking the spot of magic side. Plus touma is the only one that could take on a fire of a cannon that can take out a whole city type of magic.
Imagine Breaker = UBER HAX GAR POWER!!! that even if the user is a normal immortal guy its fine
Redirection = MAX CONTROL OF PLOT!!!! the plot is on accelerator's side and he will always win!!!
As for the others..... they get pawned tons of times. Well that's my opinion.