Ok, as an advise for battling Akron.... I recommend first you make all three players immune 100% for dark and death....dark resistance will protect you from many abilities in this battle and death 100% resistance will surely protect you from instant death and that by upgrading your equips to level 5 (max level) (for me I used for lance :Mage hat,Ninja cloak and Shadow blaster - for Natalie:Pope hat,Pope dress and Sentinel-for Matt :Ninja hood,Officer coat and Rune blade...that also will make some resistance for doom )
Second,I recommend to get rid of rune claw and try not to hurt others so they won't heal Akrons .