How about making a fic with Ben ten who lost everyone but gwen falling through a portal after teaming up with his rouges against Vilgax / ghost freak who have Merged like venom
After vilghost killed max and had the robots kill bens family and injuring gwen charmcaster throws the charms at Ben along with her uncles items who he reluctantly parts with he may be evil but he'll be dawmed if he lets vilgax take over his plannet he wants to take over
Ben overloads ubchuck by eating the runes/charms letting out a blast full of energy that filled the whole dimension of upchucks races stomach dimension
let's put a huge blast a dimensions worth giving himself insane damage almost killing him but the omnitrix saves him
gwen has been almost fatally wounded and charmcaster is trying to stop there fall to there suposed death falling in with them
Not knowing where its going she at least try's to shield all of them because charmcaster is not really evil
They land in dc in front of the teen Titans tower (raven )who promptly calls batman
All three passed out the justice league shows up soon after
Slightly broken Ben whos coping with Gwen bieng in a coma and all his loved ones bieng dead
His watch has enterd self repair mode something asmuth worked his ass off incase he died and was unable to fix it after a hard battle
It brings back his original ten aliens till the omnitrix fixes itself tho ghost freak is replaced with the mummy alian and wild mut is replaced by Frankenstein
Gwen will later come out of coma with healing
(Harem(Gwen charmcaster raven mabie Wonder Woman and mabie idk (harly or poison ive )