...ぬ => Not (Negative) N3
Emphasize negative meaning
が必要 => need; necessary N4
必要がある => Need/Need to N4
ねばならない/ねばならぬ/ねば => have to do; must; should ~ N2
~ぬうちに => While not....; before... N1
Time
ぬきにして/~ぬきで => Exclude A; Stop/end A; Without A N2
Miscellaneous
~ぬばかり => As if; as though N1
Situation
~ぬまに => without one's knowledge, without noticing N1
Time
ぬく => Do A until the end/last N2
Will, Decision, “Doing”
[要「よう」]するに => A. In short/put simply, B N2
Adjectival, Descriptions
要するに => in short; in a word; to sum up; to put it simply ~ N2
ぬまでも => not to say; although it does not reach the level of ~ N1
Description