Focus on your staff. Otherwise, emblems, I guess.

Get 100 Firefighter/Cryophile/Aeronaut (depending on which elements you are using), and 25 Lovers. 100 Professional is a must for any damage dealer (you can find them on 7 Year Kill fists). Get 8 Tutor stacks to level up a legendary Infernal Staff. Rather than fully perfect it, you can opt to only reset for the first mystery room, it divides the number of resets by 3 and you can still be lucky and get bonus levels from the other 2 (at best) mystery rooms. It uses less gencies, too.

There are a few R40s int accessories that don't require access to the Land of Carnage: Arcadia from stealing from the Zombie King in CoO5 (only the first time, once per cycle), Kitty's Ears (unique) from stealing from Marjoly (the fight can be unlocked at the Assembly if you have 99+ felonies on one character), Usagi's Journal from fully clearing the Dark World (once per cycle) (use a guide, some conditions to unlock Dark World stages are almost impossible to find on your own).