It reminds me of Rubeus, like [name_m]Hagrid[/name_m]'s first name in [name_u]Harry[/name_u] [name_m]Potter[/name_m]. I’d probably spell it Rubes, but it’d get pronounced to rhyme with cubes a lot.
It sounds familiar to me but I’m wondering if it’s because it almost reminds me of Rubik’s, as well as [name_m]Reuben[/name_m]/Ruben.
I like the look of @ethelmary suggested spelling of Reubes but I would suggest spelling it Rubis since I don’t think that would get any mispronunciations
[name_f]My[/name_f] son is [name_m]Reuben[/name_m] and I call him Reubes a lot, said roobs. I’d spell it Reubis for the spelling, Rubis reminds me of Rubix cube. Maybe even Reubus. It could work!
So, this is just [name_m]Rufus[/name_m] with a B instead of F. So, Rubus or Reubus would be the spelling that gets me there the most effectively. I also think of Rubeus [name_m]Hagrid[/name_m], and I do like Rubeus better than Rubus/Reubus personally, but only slightly.
Rubus just looks so much cleaner than any of the suggestions with a double vowel. I think I would be mispronouncing most of them. I definitely vote Rubus!