why not, you can take lvl 20 to hard, 40 to vhard, so 60 shoudl go to ultimate, anyway i will do trial by error by lvling up 3 more times. You don't need to beat dark falz to take your feller to the next difficulty as long as he's the appropriate lvl. and i recently found that as long as one of the characters going into multiplayer with you is that far along you can have the lower lvl as player 1. But i will certainly find out for myself here in a little bit anyway, so i will post triumph or failure 
Sirtsu HUmar Viridia lvl111 Ult caves [lvl 101 Rati]
Baron0 HUmar Yellowboze lvl115 Ult Mines [lvl 200 Rati]
ranchon RAmarl Pinkal lvl64 Ultimate forest [lvl 155 Nidra]
Ka HUmar Skyly lvl43 Hard Ruins [lvl 200 Diwari]
DarkLoduss FOmar Skyly lvl 44 hard ruins [lvl 200 Nidra]
Currently searching for: Yasha, Angel Harp, 4 more God/Power, 2 More God/Arms
Baron0 HUmar Yellowboze lvl115 Ult Mines [lvl 200 Rati]
ranchon RAmarl Pinkal lvl64 Ultimate forest [lvl 155 Nidra]
Ka HUmar Skyly lvl43 Hard Ruins [lvl 200 Diwari]
DarkLoduss FOmar Skyly lvl 44 hard ruins [lvl 200 Nidra]
Currently searching for: Yasha, Angel Harp, 4 more God/Power, 2 More God/Arms