Another plot could be that a powerful relic from the Warframe universe is discovered in Remnant. This attracts the attention of both the Tenno and the various factions in RWBY. The Tenno must race against time to retrieve the relic before it falls into the wrong hands. Along the way, they form alliances with Ruby and her friends. The fanfic could include epic battles where the Tenno's Void powers are combined with the RWBY characters' Aura and Semblances.
One idea could be that the Tenno from Warframe are sent to the RWBY universe due to a trans - dimensional rift. They team up with the RWBY characters to fight a new common enemy that is a fusion of the Grineer and Grimm. The Tenno can introduce their advanced technology and combat skills, while the RWBY characters show their unique Semblances and teamwork.
Maybe the Warframes themselves start to take on some characteristics of the RWBY world. For example, a Rhino Warframe could gain some of the strength and appearance traits of a Beowolf. The story could then focus on how the Tenno adapt to these changes and how they use them to help the RWBY teams in their battles against Salem's forces. The fanfic could also explore the cultural differences between the two universes and how the characters overcome them to work together.
Chapter 421, ", Supreme Command?", is the clearest early answer because it turns Gu Hang's situation into a concrete plot event. The chapter turns that into something concrete by moving from When Gu Hang first proposed to take the initiative to attack, I... to Ripping open the energy shields of four Green Skin Ships, including....
Chapter 443, ", the mobilization ratio must be higher!", is the clearest early answer because it turns Great Chieftain's situation into a concrete plot event. The setup is Inside the Temir Star System, on the flagship 'Giantsfield' of the..., but the pressure keeps building through The dripping blood slightly calmed his state of mind, and he was.... Once the chapter lands on The earliest had been conquered for over fifty years;
Chapter 381, ", Reverse His Mother's!", is the clearest early answer because it turns Star Sector Government's situation into a concrete plot event. Early on, As for Korolya, having a development level maintained at grade 1 is.... By the end, According to estimates, all the population on the Fatchess Tri-Star,.... Inside the broader family politics storyline, the chapter closes with I was planning to say it owed 1k, but adding a thousand words doesn't seem right...
Chapter 472, ", Striking the Heart", is the clearest early answer because it turns Skugg Beasts's situation into a concrete plot event. The chapter turns that into something concrete by moving from Titus had unified the Iron-Tooth Clan and sparked a monumental... to Their primary use was still as food.. What makes it stick is that the chapter closes with Green Skins did not live long and had no process of birth, aging, sickness, and death.
Chapter 310, ", Apology", is the clearest early answer because it turns Alliance's situation into a concrete plot event. It opens with What was Blackbird Heavy Industries' slogan again? and closes on The Alliance indeed did not support idleness; even if temporarily out....
Chapter 452, ", So You've Joined Them Too", is the clearest early answer because it turns Terminator Power Armor's situation into a concrete plot event. A useful checkpoint is the way the scene starts with When Zhong Jihua saw Matins and the group of Phoenix warriors burst... and follows through with Lifting his Powered Sword, still ablaze with lingering lightning,....
Chapter 356, ", Subspace Smuggling Plan", is the clearest early answer because it turns Nest Capital's situation into a concrete plot event. A useful checkpoint is the way the scene starts with You all can see, without any need for me to say it, countless... and follows through with Inside the flesh body of Fino City, small but very maliciously placed.... By the close, The four century-old veterans from Phoenix were fine;
Chapter 393, ", Hongjian Star Joins", is the clearest early answer because it turns Fatchess Tri's situation into a concrete plot event. The chapter turns that into something concrete by moving from Regarding the reforms of Fatchess Tri-Star, even if the plan devised... to This is still achieved under circumstances where Korolya has suffered....
Chapter 492, "Never Worry About Gu Hang's Loyalty!", is the clearest early answer because it turns Imperial Guards's situation into a concrete plot event. The setup is In the entire Holy Terra, which faction holds the most powerful..., but the pressure keeps building through Without a doubt, it is the Imperial Forbidden Army..
Chapter 420, "Terrifying Spiritual Energy, Tearing Through the Ship's Shield", is the clearest early answer because it turns Fleet Commander's situation into a concrete plot event. It opens with This put him in a difficult position all of a sudden. and closes on Even with the three cruisers focusing fire, there was no way the....