I run through the entire game on a New Game Dante Must Die! difficulty run with the Legendary Dark Knight, obtaining 100%. The 100% category is defined as collecting all permanent upgrades, which are all blue orbs, purple orbs, Devil Arms, firearms, and skills for the Devil Arms, as well as all S ranks for the King of Hell picture. The choice of using LDK is only for Mission 1, afterwards, it only becomes a cosmetic change.
There is one death during Secret Mission 5, but it is done during the intermission, so there is no time lost in the in game timer.
