Another interesting concept is a time - travel crossover. Have a character from Highschool DxD travel back in time to an era in a different fictional universe. They could end up in the world of Game of Thrones and have to deal with the politics and power struggles there, while also using their DxD powers. It would be really cool to see Issei trying to survive in Westeros and maybe even form an alliance with Daenerys using his devil powers.
One idea could be to introduce characters from another popular anime into the Highschool DxD universe. For example, having Naruto characters in the DxD world. They could bring their unique jutsus and ninja skills, which would create interesting interactions with the devils, angels, and fallen angels in DxD. Maybe Naruto could use his shadow clone jutsu to outwit the devils in a battle of wits.
You could also do a crossover where the Highschool DxD characters end up in a post - apocalyptic world like that of The Walking Dead. The devils, angels, and fallen angels would have to work together to survive against the zombies. Their powers would be put to the test in a whole new way. For instance, Rias could use her magic to protect a group from a horde of zombies, while Akeno could use her lightning powers to electrocute large groups of the undead.
Chapter 380, ", It is necessary to maintain respect for Gu Hang", 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 Regarding how much tax each world should pay, the Empire had... to After six years, add the forty billion back..
Chapter 247, ", Charge into the Fray", is the clearest early answer because it turns Lion Tanks's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Drex was certainly a great noble of the Luman Kingdom; throughout the... and follows through with At least destroying the Sentinel Mechas near the Knight Titans wasn't....
Chapter 382, ", He Really Believed It!", is the clearest early answer because it turns Star Sector Government's situation into a concrete plot event. It opens with This is the ruling center of the Fatches Family. and closes on The Fatches did not have their own fleet; the few small ships they....
Chapter 374, ", Alliance Shipyard", is the clearest early answer because a shaky connection becomes usable in the plot. Early on, This was yet another replenishment of the starship's combat weapons,.... By the end, Gu Hang had ambitions for a full-chain shipyard, but in practice,.... Inside the broader faction conflict storyline, the chapter closes with Still owe 16k, which gives faction conflict a stronger narrative position and pushes the power growth onward.
Chapter 393, ", Hongjian Star Joins", is the clearest early answer because it turns Heijian Star's situation into a concrete plot event. Early on, Regarding the reforms of Fatchess Tri-Star, even if the plan devised.... By the end, This is still achieved under circumstances where Korolya has suffered....
Chapter 292, ", Imperial Tax", is the clearest early answer because it turns Dragonhawk Star Domain's situation into a concrete plot event. It opens with A world that should have been rich and beautiful, what a pity, the... and closes on 1 Tax Currency is equivalent under Empire standards to the total.... The key payoff is that the chapter closes with The planets are still there, still under the administration of their respective Star Sectors, Star Domains, and Cosmos Domains.
Chapter 280, ", The Voice of Fury", is the clearest early answer because it turns Anat's situation into a concrete plot event. The chapter gives readers a real answer by opening on Anat's expression became stern and tense. and ending on Aside from the few that were slashed by the warriors in close.... In story terms, the chapter closes with There will also be a chapter tomorrow at noon., which gives power growth a stronger narrative position and pushes the power growth onward.
Chapter 355, ", I Assure You", is the clearest early answer because it turns Brigade's situation into a concrete plot event. The chapter turns that into something concrete by moving from Even a corrupt magic dragon had flown to the battlefield. to You must destroy them for me!.
Chapter 236, ", Success in Killing the God! Death of the Evil God!", is the clearest early answer because the violence around Tax Currency becomes final instead of hypothetical. The chapter gives readers a real answer by opening on Primal Fury Owl planned to slip away, no longer moving forward,... and ending on The more furious Evil God summoned even more lightning, striking....
Chapter 291, ", The Visitor from Beyond", is the clearest early answer because it turns Gu Hang's situation into a concrete plot event. Early on, When will the Dragonhawk Third Legion arrive?. By the end, Transporting a million troops isn't easy..