Ok berries I’m in need of some unique middle names for boys (totally open to unisex or leaning feminine also). I’m feeling super uninspired. I know “unique” is subjective, but whatever you can come up with.
Some inspiration:
[name_u]Sparrow[/name_u]
[name_u]Jupiter[/name_u]
[name_m]Locke[/name_m]
[name_m]Apollo[/name_m]
[name_m]Friday[/name_m]
TIA 
Hmm…some of these are more unusual than others, but your list reminds me of:
Arrow
[name_u]Atlas[/name_u]
[name_u]Bowie[/name_u]
[name_m]Callister[/name_m]
[name_m]Caspian[/name_m]
[name_u]Cedar[/name_u]
[name_m]Cosmo[/name_m]
Dare
[name_u]Dune[/name_u]
[name_u]Ever[/name_u]
[name_u]Fable[/name_u]
[name_m]Fielder[/name_m]
[name_u]Finch[/name_u]
[name_u]Florian[/name_u]
[name_u]Flynn[/name_u]
[name_m]Gable[/name_m]
[name_u]Harbor[/name_u]
[name_m]Hart[/name_m]
[name_f]Hazel[/name_f]
[name_u]Jem[/name_u]
[name_u]Larkin[/name_u]
[name_u]Lynx[/name_u]
[name_m]Lysander[/name_m]
[name_f]Maple[/name_f]
[name_u]Mars[/name_u]
[name_m]Moss[/name_m]
[name_u]Navy[/name_u]
[name_u]Ocean[/name_u]
[name_u]Onyx[/name_u]
[name_u]Orion[/name_u]
[name_u]Pax[/name_u]
[name_u]Peregrine[/name_u]
[name_u]Phoenix[/name_u]
[name_u]Poe[/name_u]
[name_f]Poem[/name_f]
[name_f]Poesy[/name_f]
[name_u]Prairie[/name_u]
[name_u]Quest[/name_u]
[name_u]Rio[/name_u]
[name_u]Rune[/name_u]
[name_u]Skye[/name_u]
[name_f]Sonnet[/name_f]
[name_u]Starling[/name_u]
[name_m]Stellan[/name_m]
[name_u]Story[/name_u]
[name_f]Sunday[/name_f]
[name_u]True[/name_u]
[name_u]Valentine[/name_u]
[name_m]Viggo[/name_m]
[name_u]Wolf[/name_u]
[name_u]Winter[/name_u]
I love @dandy_orchids suggestions, although I would have never put [name_m]Caspian[/name_m] in this lists 
Like OP said, unique is subjective. I would call #791 in the US unique.
Adair
[name_m]Alistair[/name_m]
[name_m]Amadeo[/name_m]
[name_u]Augustine[/name_u]
[name_m]Barnaby[/name_m]
[name_u]Bellamy[/name_u]
[name_u]Blair[/name_u]
[name_u]Bryn[/name_u]
[name_m]Bruno[/name_m]
[name_u]Calder[/name_u]
[name_m]Callister[/name_m]
[name_u]Cato[/name_u]
[name_m]Ender[/name_m]
[name_m]Eben[/name_m]
[name_u]Evren[/name_u]
[name_m]Finnick[/name_m]
[name_u]Jem[/name_u]
[name_m]Leander[/name_m]
[name_m]Magnus[/name_m]
[name_u]Montgomery[/name_u]
[name_m]Ozias[/name_m]
[name_m]Phineas[/name_m]
[name_m]Rhydian[/name_m]
[name_u]Sascha[/name_u]
[name_u]Sinclair[/name_u]
[name_u]Valentine[/name_u]
[name_u]Vaughn[/name_u]
[name_u]Willoughby[/name_u]
[name_u]Winslow[/name_u]
[name_m]Zebedee[/name_m]
Atlas
[name_m]Navigator[/name_m]
[name_m]Forrest[/name_m]
[name_m]Ferris[/name_m]
[name_u]Holland[/name_u]
Inidgo
[name_m]Alphonse[/name_m]
[name_m]Isaiah[/name_m]
[name_u]Kestrel[/name_u]
[name_u]Oleander[/name_u]
[name_m]Hawthorn[/name_m]
[name_u]Peregrine[/name_u]
[name_u]Micah[/name_u]
[name_u]Mars[/name_u]
[name_m]Magnus[/name_m]
[name_m]Absalom[/name_m]
[name_u]Mercury[/name_u]
[name_u]Mariner[/name_u]
[name_u]Navy[/name_u]
[name_m]Wystan[/name_m]
[name_m]Zebedee[/name_m]
Valor
[name_u]Arrow[/name_u]
[name_m]Caspian[/name_m] (not so uncommon now, though)
[name_m]Leif[/name_m]
[name_u]Lark[/name_u]
[name_u]Robin[/name_u]
[name_u]Eagle[/name_u]
Eagane
[name_m]Rhidian[/name_m]
[name_m]Fabian[/name_m]
Woodruff
[name_m]Woodrow[/name_m]
[name_m]Haywood[/name_m]
[name_m]Elwood[/name_m]
[name_u]Atwood[/name_u]
[name_m]Lockwood[/name_m]
[name_m]Sherwood[/name_m]
[name_u]Basil[/name_u]
Vasilis
[name_m]Valdemar[/name_m]
[name_u]Florian[/name_u]
[name_m]Timo[/name_m]
[name_m]Macallister[/name_m]
Vale
[name_u]Hero[/name_u]
[name_u]Lynx[/name_u]
[name_u]Sage[/name_u]
[name_u]Lux[/name_u]
[name_u]Adler[/name_u]
[name_u]Kindred[/name_u]
[name_u]Sparrow[/name_u]
[name_m]Yates[/name_m]
[name_u]Keats[/name_u]
[name_m]Keen[/name_m]
[name_m]Parks[/name_m]
[name_m]Price[/name_m]
[name_u]Grove[/name_u]
[name_m]Bramble[/name_m]
[name_u]Birch[/name_u]
[name_m]Ridge[/name_m]
[name_f]Endeavor[/name_f]
[name_m]Gable[/name_m]
[name_u]Salem[/name_u]
Cates
[name_u]Victory[/name_u]
[name_u]Thistle[/name_u]
[name_m]Hawthorn[/name_m]
[name_u]Noble[/name_u]
[name_u]Brave[/name_u]
[name_u]Onyx[/name_u]
[name_u]Denali[/name_u]
[name_u]Royal[/name_u]
[name_m]Hart[/name_m]
[name_u]Frost[/name_u]
[name_m]Kipling[/name_m]
[name_m]Roark[/name_m]
[name_m]Townes[/name_m]
[name_m]Fitz[/name_m]
[name_m]Judd[/name_m]
[name_m]Hoyt[/name_m]
[name_m]Hewitt[/name_m]
[name_m]Hardy[/name_m]
[name_m]Whistler[/name_m]
[name_m]Fisher[/name_m]
Attwell
[name_u]Dune[/name_u]
Fields
[name_m]Rhodes[/name_m]
[name_m]Rochester[/name_m]
[name_m]Rockwell[/name_m]
[name_m]Maclean[/name_m]
McCoy
[name_u]Mars[/name_u]
[name_m]Keir[/name_m]
[name_m]Rainier[/name_m]
[name_u]Rex[/name_u]
[name_u]Banks[/name_u]
[name_u]Alder[/name_u]
[name_u]Cove[/name_u]
[name_m]Creed[/name_m]
[name_m]Bates[/name_m]
[name_u]Hale[/name_u]
[name_m]Oakes[/name_m]
[name_m]Shale[/name_m]
[name_u]Rawlings[/name_u]
[name_m]Fielder[/name_m]
[name_u]Zephyr[/name_u]
[name_u]Valor[/name_u]
[name_u]Heron[/name_u]
[name_u]Cypress[/name_u]
[name_u]Kodiak[/name_u]
Rise
[name_m]Bower[/name_m]
[name_m]Anthem[/name_m]
Summit
[name_u]Merit[/name_u]
Leeds
Alpine
[name_u]Spark[/name_u]
Cosmo
[name_f]Melody[/name_f]
[name_u]Cloud[/name_u]
[name_f]Lumi[/name_f]
[name_f]Pearl[/name_f]
[name_f]Maple[/name_f]
[name_u]Noel[/name_u]
[name_u]Ren[/name_u]
[name_u]Shea[/name_u] / [name_u]Shay[/name_u]
[name_u]Frankie[/name_u]
i love beautiful word names on boys !