Last one of this puzzle.
12d Souls in hell receiving 6 of 2(11) ?n?i?i?u?l? 6 is legend and 2 is pliocene. insidiously/invidiously fit but can't make any sense of this.
Thank you very much scotman and roslyn251254 for your analysis. I would never have thought of dis for hell. This crossword was set by 3 compilers rather than the usual 1: It has some interesting challenges!