ablative case vs oblique case

ablative case and oblique case both are nouns.

Word	Noun	Adjective	Verb	Adverb
ablative case	Yes	No	No	No
oblique case	Yes	No	No	No

As nouns, oblique case is a hypernym of ablative case; that is, oblique case is a word with a broader meaning than ablative case:

ablative case: the case indicating the agent in passive sentences or the instrument or manner or place of the action described by the verb
oblique case: any grammatical case other than the nominative

Other hypernyms of ablative case include oblique.

ablative case (noun)	oblique case (noun)
the case indicating the agent in passive sentences or the instrument or manner or place of the action described by the verb	any grammatical case other than the nominative