Some Really Good Violence

Ever want to put some really good violence into your campaign world, but fear that it will disrupt what you’ve worked so hard for? Try an alternate universe! What in the H E double hockey sticks is he talking about?!?
As many of you know, my world is Fletnern. It was started about 30 years ago (man that hurt - thinkin’ I’m that old). I have built and nurtured this world for 30 years, and the thought of having a massive world war that will likely kill a bunch of main characters (at least NPCs) and completely change most of what I have going currently is scary to me. Oh, I’d love to see it, but I don’t are risk it.
Then it struck me - parallel universe. Hey, if it works in the comic books, it should work here. A couple of minor changes to give it a slightly different feel, and advance a cold war into a war on the brink of exploding. Then, a friendly neighborhood time traveling titan (yes, I have more than one in the world) and the player character (or party of PCs) is replacing a recently assassinated version of himself on a different, but seemingly similar, world. Now, I can have my huge battle, and after the character takes part in the big war, he/she/it can go home - back to the normal world that still exists as I designed it, but with fond memories of ripping the world apart.
I have to tell you - I love this idea so much, I’m going to use it a lot more than once. Not only does it work fantastically well for one campaign, but it helps me keep one campaign’s huge action from completely disrupting another campaign’s normalized action.