So I also went with the Xindi, but quite a different take on them. For starters I made the Xindi a Non-Aligned subgroup connected by a keyword (like Khan and co, or the Think Tank,) so you could splash them into any non-Borg deck, but they work best when working together. Much like their fellow 22nd Century residents Starfleet they care about species, but where as Starfleet rewards the player for having a diverse range of species, the Xindi turn their species diversity (and their opponent's species) into a weapon.
Once you have a few of them out you can really start messing with your opponent, making their personnel more expensive, taking out their events en masse, drawing and spending more on dilemmas against them and even hunting down members of specific species with cheap but powerful warships. Also as residents of the Delphic Expanse they get home advantage, able to attempt any mission in the region and travel further within it. Oh yes, and even the opponent's homeworld isn't safe if you manage to Launch a Devastating Attack against it.
Near Enemy Homeworld, Launch Devastating Attack
Degra, Xindi Oppenheimer
Dolim, Xenophobic Commander
Jannar, Thoughtful Councillor
Kiaphet Amman'sor, Councillor Of The Ibix Dynasty
Rajiin, Xindi Operative
Shresht, Belligerent Councillor
3 *Parallel Evolution
To play this event you must command 3 Xindi personnel. Plays in your core.
Your Xindi personnel may attempt and complete your Region: Delphic Expanse missions.
When your Xindi personnel is facing a dilemma, you may discard a Xindi personnel of a different species from hand to make him or her gain a skill from that discarded personnel until the end of this mission attempt.
*Near Enemy Homeworld, Launch Devastating Attack
Astrometrics, Engineer, Programming, Security, Treachery and Cunning >40
When you complete this mission, choose an opponent's headquarters mission. Randomly select a personnel at that mission to be killed for each different species of personnel who uses his or her skills to complete this mission.
"Open the vortex… Set a course for Earth!"
– 4 –
4 *Degra, Xindi Oppenheimer
Astrometrics, Engineer, Geology, Leadership, Physics, Science,
When this personnel uses a skill to complete a mission, you may destroy opponent's events with a total cost less than or equal to the number of Xindi personnel of a different species you command. You may do this only once each turn.
“Deploy the weapon.”
Integrity: 4, Cunning: 7, Strength: 5
2 *Dolim, Xenophobic Commander.
Leadership, Navigation, Officer, Security, 2 Treachery
Commander: Xindi Warship. Xindi.
If you command Xindi personnel of three different species, you may discard a card from hand to begin combat or an engagement involving this personnel. If you win, name a species. Randomly select an opponent's personnel of that species involved to be killed.
“Your traitorous bloodline will end at the tip of my blade.”
Integrity: 1, Cunning: 6, Strength: 7
2 *Jannar, Thoughtful Councillor
Anthropology, Honour, Law, Programming, Science
When you play this personnel you may download Parallel Evolution or a Xindi personnel.
"What we do is for our children's future. Remember that."
Integrity: 6, Cunning: 6, Strength: 5
3 *Kiaphet Amman'sor, Councillor Of The Ibix Dynasty
Acquisition, Diplomacy, Engineer, Leadership, Physics
While you command Xindi personnel of three different species, the first non-Xindi personnel your opponent plays each turn is Cost +1.
"It is easier to count the stars in the sky, than for an Aquatic to come to a decision."
Integrity: 5, Cunning: 7, Strength: 2.
2 *Shresht, Belligerent Councillor
Exobiology, Security, Treachery
When your event or interrupt with “species” in its gametext is about to be destroyed or prevented, if you command Xindi personnel of three different species, you may kill this personnel to prevent that.
“We are acting on behalf of all Xindi.”
Integrity: 4, Cunning: 5, Strength: 5
4 *Rajiin, Xindi Operative
Biology, Exobiology, Intelligence, Programming, Telepathy, Treachery
Name a species present with this personnel. When your opponent begins a mission attempt involving a personnel of that species, you may draw one extra dilemma and spend one extra in total cost on dilemmas for each Xindi personnel of a different species you command (limit 3.) This effect lasts until this order is executed again.
"There's a reason I was taken from my home. I have certain gifts."
Integrity: 4, Cunning: 6, Strength: 6.
4 Xindi Warship
To staff this ship you must have a Xindi personnel aboard. While you command three different Region: Delphic Expanse missions this ship is Range +2. This ship is Weapons +1 and Shields +1 for each Xindi personnel of a different species you command (limit +5.)
"There are five distinct species of Xindi, and five distinct opinions on which one is dominant."
Range: 6, Shields: 4, Weapons: 4
All the Best,