RWBY/XCOM

Okay, so I guess I'll do a write up of how I'd do a RWBY/XCOM crossover since I had been pretty adamant about ideas I had for how it could work.

So, making a long story short, to keep up with the idea that the OG crossover did, I'm having RWBY go to XCOM's world, set during XCOM 2, namely through ADVENT experimentation regarding opening holes in space-time. It'd be hard to find a particular moment in Post-V3 continuity where it's just the four members of RWBY, with the closest part being them on Argus Limited. During their second round with the Grimm on the train, the portal opens and the girls end up getting sucked into the portal along with the Lamp.

The girls wake up and find themselves being experimented upon by ADVENT. To Ruby's shock, she discovers the Lamp on one of the tables. By this point, they know about the Lamp's Grimmlure potency, but are unable to grab it. Making matters worse, the experimentation they underwent has not only caused them to temporarily lose their Aura but this has helped ADVENT make some headway into the Avatar Project. Thankfully, before any permanent damage is done to them, an XCOM team busts in and rescues them, but they're unable to recover the Relic.

The XCOM soldiers bring RWBY back to the Avenger where they tell their side of the story to the Commander, including the Relic. Of course, this is a lot to take in, but given how the XCOM had been doing battle with aliens for years, "I came from another universe where we have special spiritual powers that the aliens have siphoned from us and they have a magical monster luring Relic that we need to bring to Atlas" is something they can easily consume. The Commander notices Ruby's eagerness and even fondness for weapons and he offers to help them with retrieving the Relic, since even though it's (at least to RWBY's knowledge) useless as it is, the longer ADVENT has it, the more destruction it will unleash.

Throughout the beginning chapters, RWBY get to know the members of XCOM, with Ruby herself making fast friends with Dr. Shen, who helps create temporary devices to supplant their lack of Semblances, such as accelerating boots for Ruby, drone control for Weiss, holograms for Blake, and a built in heat-sink for Yang's arm that she could use to fire off a large blast. Now, it's only a matter of time before the cast regain their Aura and thus, they're able to fend off without those devices, to which they hand off to the rest of the XCOM members.

This is already pretty long, so I'll end it with an idea for how the climax is going to go down. Namely, ADVENT, while unable to wrap their head around the concept of Aura, are able to at the very least use the aspect of the Auras they took to modify their own soldiers. In fact, it's this that causes XCOM to find modified versions of ADVENT soldiers that use RWBY's Semblances to an extent and their inevitable autopsies resulting in Shen being able to build the heat-sink and dash shoes for Yang and Ruby. Their aura returns and XCOM beings the fight to the very ADVENT base that is holding the Relic, which ADVENT hasn't cracked the code of and summoned Jinn, but to them "hey, it brings these weird monsters from the other dimension that we could mentally take over and mutate to suit our needs." ... In fact, I kinda want to do a scene where ADVENT accidentally summon Jinn by saying something in their tongue that sounds phonetically similar to her name and they instantly freak out over her appearance to the point where they don't even bother to listen to who she is and what she does (for all they know, it's some sort of weird human device that enlarges people) and end up not using the two remaining questions she has.

I wouldn't expect this to be a lengthy story. About 12 chapters broken down into mini-arcs.

    Chapters 1 & 2: RWBY going to XCOM
    Chapters 3 & 4: RWBY's first time fighting with XCOM, which also leads to them finding the ADVENT Facsimiles (what I call the ADVENT members that have RWBY's Semblances) before killing them, dissecting them, and creating the upgrades for Ruby and Yang.
    Chapters 5 & 6: Shen's Last Gift and the subsequent recruiting of the Spark Trooper, which Ruby easily compares to Penny. (Funny enough, this is XCOM 2's version of MECs, which means Yang and Blake don't have to be the two-headed mecha I envision in my nightmares)
    Chapters 7 & 8: ADVENT abuse the Relic's Grimmlure and now XCOM have to contend with fighting Grimm on top of aliens. One of the members of XCOM dies and this is where RWBY's auras return finally.
    Chapters 9 & 10: Reapers, Skirmishers, and Templars get recruited to XCOM.
    Chapters 11 & 12: A ten-man XCOM team raid ADVENT, fight an Avatar with its own Aura and Semblance, get the Relic, make the portal to return to Remnant, and Ruby wishes XCOM good luck in defeating ADVENT. RWBY return to find JNROQM were waiting for them in Argus. This, naturally, leads to a crap ton of changes for RWBY's story. For one, they don't find out about Jinn or the questions or Ozpin's dirty little secret, but that is another story for another time, a possible sequel where it's XCOM that arrives in Remnant?