i beat him usuing only 1 untouchable and 1 small lfie star used it bout mid way through the space fight then goit up to him on the rock and used my devil trigger, only upgraded it once used grenade launcher to kill alot of stuff, when the fire dragon came out and started destroying things i used the untouchable, stood in teh lava with devil trigger and finished mundus off
first battle. you can hold a button to fly faster so you can dodge things easier....just practice and be patient..very easy but repetitive
second battle (this is what i do, it works for me on all difficulties) equip shotgun. whenever you have devil trigger hop right up to his face and slash away with his sword and DODGE his attacks...sooner or later he will summon a lava dragon, if you kill it by reflecting it's fireball back at him he WILL die and give you a large green orb. use shotgun to destroy orbs before mundus uses them against you. keep hacking and slashing.
this is what i did to get a S on him on DMD...takes practice and some luck
PSN: pillowpants41.Religion is regarded by the common people as true, by the wise as false, and by the rulers as useful.
I found that round trip was really good for damage during the ground phase. I think it took off like 5 % for every dt'd round trip plus mashing on the shoot button when not dodging also helped the process along. Overall I didn't find him that hard on the ground in the air he is annoying as all hell though lol.
For the air battle: You should almost never be sitting still, you have to constantly avoid the stuff getting thrown at you. I say *almost* never because there are brief periods when you get up close where he does not throw anything that you can remain stationary and spam the attack button. Like seriously spam, I had to adjust the placement of my right hand to spam it fast enough cause my fingers were too slow. As for dodging, with the meteor shower I move in slow circular patterns across the screen to avoid it. Same with the red and white lasers. The lightning and rocks should be easy to avoid. Hit the devil trigger when you get it powered up enough. You should constantly be firing, at least I always was. I was never not firing.
The ground battle is a *****. I had to use one devil star near the end.
ride the tiger you can see his stripes but you know he's clean