The best strategy I've found for Julius is just to spam Balloon. It doesn't even have to be Balloonra or Balloonga. Just laying basic balloons everywhere works. You can be around lvl 40 and beat him in a few tries that way. But I mean really spam the crap out of balloon. If you only lay one set of balloons down he'll mostly run right through them (taking some damage) and will hit you. But if you can get the time to lay down 2 or 3 sets, it is highly likely he'll be stunned by some of them, giving you time to lay down more balloons. Rinse, repeat.
For his long punching combo, which he'll use a lot if you keep your distance, either lay down lots of balloons or just block and counterattack. The last couple hits will often break through your block if you don't counter, but countering actually puts you out of harm's way, and deals good damage too. For his building jump attack, just flowmo off the walls to avoid him or take the hit and heal immediately (assuming you have abilities to save you).
For his lightning attacks, spam block to avoid the lightning from above, then treat his attacks just like you normally would: block and dodge. If you freak out and run around like a chicken with your head cut off you're going to get clobbered by simple attacks you normally wouldn't get touched by. The only little things to remember are try to dodge sideways, since many of his attacks will shoot lightning in a straight line, and even if Second Chance/Once More will save you, avoid the building attack, since it disables your commands.
For his long punching combo, which he'll use a lot if you keep your distance, either lay down lots of balloons or just block and counterattack. The last couple hits will often break through your block if you don't counter, but countering actually puts you out of harm's way, and deals good damage too. For his building jump attack, just flowmo off the walls to avoid him or take the hit and heal immediately (assuming you have abilities to save you).
For his lightning attacks, spam block to avoid the lightning from above, then treat his attacks just like you normally would: block and dodge. If you freak out and run around like a chicken with your head cut off you're going to get clobbered by simple attacks you normally wouldn't get touched by. The only little things to remember are try to dodge sideways, since many of his attacks will shoot lightning in a straight line, and even if Second Chance/Once More will save you, avoid the building attack, since it disables your commands.