21st Testing Protocol: Similar series
Galactic Bonds
by Jennifer Estep
4.05 · 134 ratings
audiobook · science fiction · magic · futuristic · fantasy · m-f · career professional · fated-mates · paranormal · commander · competent heroine · graphic-violence · fighters · open-door · military · death · super rich hero · independent heroine · war · cold hero
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The Adventures of a Xeno-Archaeologist
by Jenny Schwartz
4.26 · 124 ratings
futuristic · military · science fiction · audiobook · aliens · length-short · length-medium · angst · paranormal · found-family · dual-pov · fantasy
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86—EIGHTY-SIX Light Novel
by Asato Asato
4.40 · 129 ratings
length-short · war · young adult · dystopian · science fiction · military · dark · glimpses-kisses · racism · audiobook · high fantasy · death
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Hell Squad
by Anna Hackett
4.22 · 293 ratings
military · aliens · science fiction · m-f · audiobook · dystopian · futuristic · length-short · independent heroine · length-novella · alpha male · explicit-open-door · cold heroine · war · cold hero · commander · erotica · height-difference · vengeance · warrior-heroine
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Imperial Princes
by Mina Carter
3.69 · 36 ratings
science fiction · futuristic · aliens · length-short · m-f · military · open-door · rape-mc · abuse · rape · erotica · length-novella · cruel hero · slavery · explicit-open-door · strong heroine · suspense · commander · harems · pregnancy
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The Ravager Chronicles
by Sara Page
3.80 · 24 ratings
futuristic · reverse harem · aliens · science fiction · multicultural · poly · length-short · menage · military · demons
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Men of Omaron
by Juno Wells
4.01 · 31 ratings
futuristic · science fiction · military · length-short · aliens · fantasy · length-novella · pregnancy · royalty · third-person-pov · explicit-open-door · m-f · alpha male · dual-pov
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Kif Warriors
by Kiki Burrelli
4.04 · 44 ratings
military · m-m · science fiction · queer · length-short · fated-mates · omegaverse · aliens · height-difference · dub-con · abduction · non-human-hero · first-person-pov · dual-pov · length-novella · slavery · fantasy · pregnancy
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The D.I.R.E. Agency
by Joni Hahn
4.10 · 55 ratings
futuristic · science fiction · length-short · suspense · military · fantasy · superheroes · paranormal · length-novella · time travel · erotica · betrayal · contemporary · urban fantasy · bdsm
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Ultimate Passage
by Elle Thorne
3.65 · 22 ratings
audiobook · military · multicultural · futuristic · science fiction · length-short · fantasy · aliens · non-human-hero · paranormal · urban fantasy · magic · erotica · new adult · shapeshifters · length-novella
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The Ragrim Conflict
by Nessa Claugh
4.26 · 17 ratings
explicit-open-door · third-person-pov · dual-pov · independent heroine · aliens · audiobook · m-f · science fiction · mental-trauma · non-human-hero · caretaking · strong heroine · sweet-hero · men in uniform · length-short · forced proximity · competent heroine · fighters · military · abuse-non-mc
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The Old Ways
by Corin Cain
4.06 · 17 ratings
science fiction · audiobook · paranormal · military · poly · reverse harem · length-medium · length-short · aliens · menage · alpha male · fated-mates · royalty · fantasy · omegaverse · length-epic
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Aliens of Dragselis
by Zara Zenia
4.21 · 19 ratings
military · science fiction · shapeshifters · fantasy · futuristic · paranormal · length-short · m-f · aliens · audiobook
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Mermaids of Montana
by Elsa Jade
3.78 · 9 ratings
length-short · paranormal · science fiction · military · aliens · shapeshifters · futuristic · fantasy · m-f
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Apocalypse Joy
by Jackie Oliver
4.00 · 9 ratings
young adult · dystopian · military · audiobook · horror · paranormal · science fiction · fantasy · length-short · alpha male · betrayal · survival · love triangle · other-man-woman · poly · length-medium · suspense · m-f-m · mystery · futuristic
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Intergalactic Enosis: The Pyxis System
by Aurora Welkin
4.36 · 11 ratings
science fiction · multicultural · fantasy · length-short · futuristic · paranormal · shapeshifters · military · poly · aliens · reverse harem
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Hunted Relics
by Sybur Phyre
4.33 · 15 ratings
science fiction · military · m-f · length-short · length-novella · fantasy · aliens · non-human-hero · death · alpha male · vengeance · rape · paranormal
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