Berserk of Gluttony is a dark fantasy light novel series which later adapted into a manga and anime, that follows Fate Graphite, a young man cursed with the “Gluttony” skill, which leaves him constantly hungry but also grants him the ability to absorb the powers and skills of those he kills.
As the anime of it is getting popularity, fans are doubting about the future wife of Fate in Berserk of Gluttony. Though here Roxy Hart clearly looks like has an upper hand in this matter but let’s drive into it and try to answer the possible outcome.

How the Story Begins?
If we dive into the story, the story starts with showing a world where magical skills and abilities play a significant role in determining one’s status in the society and there we see Fate Graphite, a boy borns without magic, always humiliated by people born with fortune and there we see Roxy Hart, a holy knight who never judged Fate and always stands by his side.
As the story continues, Fate realised, he is cursed with the Gluttony skill, which makes him constantly hungry but lets him absorb the powers of those he kills. His journey intertwines with Roxy Hart, whose relationship with Fate grows from a master-servant dynamic into a deep romance, central to the story and fan discussions about his future wife.
Fate & Roxy – A Growing Bond
Fate later starts working under Roxy for Hart family. He admires her but hides his Gluttony skill, fearing rejection. He later saves Roxy various times including from a Divine Dragon but eventually his secret gets revealed to her, but she accepts him, saying she could never hate him. This strengthens their bond, and in the light novel, Fate admits he loves Roxy, and they share a kiss, signaling a near-official romance despite ongoing challenges.

Is Roxy Fate’s Future Wife?
As the Berserk of Gluttony light novel series has not yet concluded, and thus Fate’s future wife is not definitively confirmed. But it won’t be wrong to say that Roxy Hart is the most likely candidate based on the current narrative. Their romantic development is a key focus of the story, with Fate openly expressing his love for Roxy and their relationship progressing steadily.
Talking about the other female characters, such as Myne or Eris, who have shown interest in Fate, Roxy stands out as his primary love interest. Myne, who possesses the ‘Wrath’ skill, has confessed feelings for Fate but seems to accept that Roxy is his primary romantic partner for now, even implying she might wait for him in the future due to her immortality.
Eris, on the other hand, has a more teasing, big-sister-like dynamic with Fate, making a romantic relationship with her less likely.

Conclusion
So, if we have to conclude this, then in Berserk of Gluttony, Fate Graphite’s future wife is most likely Roxy Hart, specially based on their deep romantic connection and significant moments like their kiss in the light novel.
Though their are some other female characters that we have already discussed above though have shown interest on Fate but as of now doesn’t seem to be related to Fate in that way. So, at the end, Roxy Hart is very likely to be the wife of Fate Graphite.