I don't care how - time travel or any AU - but Hux met general Anakin Skywalker and became really fascinated by him. A Jedi who understands how military works and respects it, something what Force users rarely do. Hux does everything he can to prove being worthy of Anakin's notice, and get uncomfortable excited when Skywalker praises him for something or feels awful if he fails his expectations (after all Hux lack of real experienced in warfare when AS is veteran). Basicly Hux and his uncontrolled, unexcepted one-side crush on Kylo's grandfather. (It could be AS as Vader, if you prefer that way)
+ Hux is not the only one fascinated by charismatic Anakin and his skills + Kylo asking his mother to end his suffering / kill him because he can't stand how everyone around him have improperly thoughts about his grandpa and hell no, he doesn't want to feel Hux's unhealthy(?) desires in Force + Anakin is accustomed to such strange behavior, Force knows he met already many people with crush on him (but he loves only Padme)
AU, Hux is embarrassed by his crush on general Anakin Skywalker
Hux does everything he can to prove being worthy of Anakin's notice, and get uncomfortable excited when Skywalker praises him for something or feels awful if he fails his expectations (after all Hux lack of real experienced in warfare when AS is veteran). Basicly Hux and his uncontrolled, unexcepted one-side crush on Kylo's grandfather.
(It could be AS as Vader, if you prefer that way)
+ Hux is not the only one fascinated by charismatic Anakin and his skills
+ Kylo asking his mother to end his suffering / kill him because he can't stand how everyone around him have improperly thoughts about his grandpa and hell no, he doesn't want to feel Hux's unhealthy(?) desires in Force
+ Anakin is accustomed to such strange behavior, Force knows he met already many people with crush on him (but he loves only Padme)