Definitions
no longer existing or functioning
insane, deranged
Psychotic
Assiduous
[your sentence here] diligent
Benevolent
positive connotation–"bene"=good
Refutation
Refute, refutable
Epiphany
a sudden, deep realization
a dilemma; uncertainty
Quandary
Conciliatory
[your sentence] promoting harmony
Ruthless
negative–"less" means without, which isn't always a negative connotation, but paired with that RU sound it's imposing
Solemn
Solemnity
Impudent
rude, disrespectful
loudly outspoken
Vociferous
Heinous
[your sentence], utterly wicked
Ignoble
negative–"i," "a," "in" etc prefixes often indicate "not" or "opposite" and noble is a positive word
Subjugation
Subjugator, subjugate
Indelible
not possible to forget or erase
Annoyance or humiliation
Chagrin
Maxim
[your sentence],
a brief saying expressing a general truth
Magnanimous
positive–like "magnificent," it also sounds big, sweeping, generous
Pallid
Pallor, pallidness
Raze
to completely destroy
A method of secret writing; secret code
Cipher
Behemoth
[your sentence here] mammoth, a large object/being
Deride
negative–"de" can give negative vibes sometimes but I think usage and context also help with this connotation
Intrepid
Intrepidity