Toaru x Rising of the Shield Hero

For this idea, I want to be a bit more inclusive of the rest of the cast of Toaru, rather than it just being focused on Touma. As much as I would like to do just that, I figured it'd be much better if I focused on some of the others too, at least every now and then.

For this idea, I want to start by focusing on how the King was a part of a group of heroes before the heroes of the sword, bow, shield, and Spear were summoned. By knowing that such a group exists, should it not also be within reason for there to have already been another group of 10 heroes before the four heroes focused on in canon?

Seven of these should be the level 5s of Academy city, while the others should be Touma, Index, and Othinus. There should be no rule against these particular heroes teaming up, as their weapons shouldn't oppose each other like the ones for the canon heroes. As such, Touma, Index, and Othinus can be a team. You can have other teams of characters as well, if you'd like. As for what you should make Index and Othinus' powers be, for Index you can just make it so she can have limited use of the grimoires in her head, and for Othinus minor use of some of her magic god powers that aren't too powerful.

The idea is that their powers should be capable of absorbing things and acquiring different forms just like the weapons in canon. This should go for Imagine Breaker as well; it starts off weak, not being able to negate anything, but after beating enemies it gains resistances and such. Maybe even have it affect the Invisible Thing. You don't have to introduce the sin thing if you don't want to, especially since that might mess up the story if it's done during the time in which the four heroes are summoned.

You can either have this take place long before canon, with focus on the 10 heroes instead, or you can have it focus on the four canon heroes, with supporting influence from this cast of Toaru characters. In other words, it can alternatively take place during canon, with the cast of Toaru having already gone on their own adventures, and with the surviving characters joining up with Naofumi's party. (I don't think any of them would really want to join the other three heroes' parties, but if you think otherwise, you're free to spread them out.) I'd prefer if you went with the second scenario, personally.

I also want the Toaru characters to have already been born in the world of Rising of the Shield Hero, rather than get summoned there. They all gain their powers mysteriously one day when they're young, and then they set off on their own respective journeys. Something like that, anyway. Touma's misfortune should still exist, as should the Invisible Thing. Due to Touma's unique circumstances, he's considered the centrepiece of the ten heroes politically, but some don't consider him a part of the group, since he's so different. If you chose the second scenario to write, then have all of this done via flashbacks or just verbal explanation to other characters.

I want certain characters of Toaru to either die or have died, depending on the scenario you choose. Other than Touma, you can decide which characters live or die, but you should probably keep Misaka or at least Accelerator alive as well. (Just a recommendation.) the characters that live should be on the lesser side, in my opinion. (As in, only a select few should survive.)

Second Scenario: Even if you manage to make it work for the Toaru characters joining other heroes than just Naofumi, I still want at least Touma's group, including Index and Othinus, to join up with Naofumi. Not every Toaru character has to be in Melromarc; some can be in other countries. Have the heroes encounter each other in the story whenever you want, but make sure that Naofumi and Touma's meeting takes place in the beginning of canon, perhaps even before the rape accusation that happens to Naofumi. Still have Raphtalia and Filo become a part of Naofumi's party, though.

Second Scenario: Try to redeem the other three heroes to be better people as the story progresses, if you can.