Meteor Rain: Mundus will give a great shout (WWWOOOAARRRR!!!) and meteors will fall from the "sky". To avoid being hit, move along the sides of your T.V. clock-wise or counter clock-wise. Either way, do not stop until the meteors stop, and stay away from the center. Mundus will only use this attack when you are far from him. He uses it QUITE OFTEN too.
Lightening Bars: Mundus shouts in this attack too (I think) and lightening bars will appear in front of you, sometimes he'll attack with one or two bars, sometimes he'll attack with three or four, I think it depends on your location on the screen.. This attack is almost in complete resemblence to Griffon's lightening bar attack, but since you are flying, you have better manueverability, and that makes it alot easier to dodge than Griffon's. He'll only use this attack when you are far from him.
Random Rune Balls: Mundus wil throw rune balls at you. They are similar to the rune balls that are shield generators, but smaller. The fly around, shooting white lasers at you, kind of like Nightmare's machine guns, but these do ALOT more damage. You can either try to destroy them, or keep on dodging their lasers, waiting for them to disappear. He uses this attack whether you're close or far from him.
Organized Rune Balls: Same as above but organized. They will circle in front of you and in front of Mundus like the shield generators. The shoot in a more organized manner, so if you get hit, its likely you will get hit alot more times. Just keep on flying and dodging the lasers, they will eventually disappear. He normally uses this attack when you are close to him, but he may also use it when you are far which is quite unlikely, but it happens. Mundus uses this attack QUITE OFTEN, and will normally combine it with...
Hand Lasers: As the name suggests, it will be lasers, coming out of his hands. His hand can generate ALOT of lasers, like his rune balls. As I said, he will usually combine this attack with Organized Rune Balls. Also like it though, he will usually use it when you are close to him, but he might also use it when you are far from him, and he also uses it QUITE OFTEN.
Lightening Rune Balls: This is his last use for rune balls (YAY!)... for this part (ARG!). Mundus will launch two balls with electricity in between the two balls. This attack is actually pretty hard to dodge, but if you destroy one ball, the whole thing is destroyed, but they spin so freaking fast, it's kind of impossible to get rid of one, and be prepared for the next. So the best thing is to try to dodge them. He will only use this attack when you are far from him.
Flying Rocks: Mundus will through big rocks at you, this is pretty much what it is. They are big rocks, but rocks nonetheless. This is the attack you can use vortex to negate altogether. You can also shoot at them until they are destroyed, but if you use vortex, you will destroy it in one hit without any damage. He will only use this attack when you are far from him.
Vertical/Horizontal Beams of Light: I have saved the best for last. This attack is similar to the eye laser of a Plasma. He will do it horizontally or vertically. To dodge it, obviously, if it shoots horizontally, fly to the top or bottom of your screen, if it shoots vertically, fly to the left or right of your screen. The ray is huge, so you have to be at the edges of the screen to dodge it, a plus side to it's largeness is that it is so large, that it takes Mundus a while to do the attack, you can anticipate it when there are runes (not rune balls) appearing around him. Also, it does a shitload of damage if you get hit, so try to dodge it. The fastest way to dodge it is to be at the center and vortex out of the way. He uses this attack QUITE OFTEN, and will use it whether you're far or close to him.