When your clone summoning skills are on cd, scepter attack still takes too long and waste too much potential damage just for the 3 clones. So like I said before outside burst confusion stacking its better to use staff for the main attack.
Go with focus instead of offhand sword:
You lose increase defense while casting mantras however you should be kiting around a rock or something and not in the open if you are setting up mantras mid combat. The bad thing about mantras is extended fights. If all your mantras are down and you have to charge them that is a considerable amount of time wasted for you and time gained for your foe.