I can't really IC this, since I'm not here, but I missed the IRC so I'm going to ask/suggest here if that's alright with you:
Any chance we could go recruit that shadow Walker guy from Earth-3? He might be useful, even as propaganda material and I bet he'd like the pickup, since we're probably the only ones with the will and knowledge to get him out of there.
How did the altered manage to simultaneously appear in multiple worlds?
If humans are infected by Origin or the Lurker, would we be safe if we escaped to another universe? If not, than shouldn't fighting or escaping the two be one of our long term objectives?
Will Steve come with us?
Can we try to copy the AM's brain using Hephaestus machinery or Doctor magic? She might not be as strong as she was before, but she's still smart and knows things. She could be useful, even with a normal body. And it would show that Steve cares for those who have helped him and humanity.
So, the Lurker is using origin to spread... What if we removed origin from the universe? Could that give us enough time to build a psychic army to kick the Lurker's ass when we brought origin back? It won't undo the damage done but it might give some of the humans here a chance, if doing so is easier and safer than sending out many interuniversal teleporters to evacuate humanity.
Would giving Origin to the altered slow down the Lurker?
What if we gave origin to the Alerted, BUT also built a ghost-ship-like entity with a will powerful enough to control the Altered and impose their will to them?
This is rather silly, but just in case it's possible: could we build a giant 5-second-reset, make it work for more seconds and use it as a time machine to revert the Lurker? Even if it can't stop it, we could use the degradation it causes to damage him. Of course, that might encounter the same problem most time machines encounter: needing more energy than is available in the galaxy.