Earth's Last Defence [DEFENDERS OF EARTH BOOK IV]

They're here.
After almost a year of preparing, the Sinestro Corps, led by the villainous Sinestro, have come for Earth. With Darkseid's death leaving a huge open space in the galaxy for a position of power, the Corps have come to Earth to claim its most powerful being, Spawn, and use him as a weapon to enslave the rest of the galaxy through fear.
Sinestro hasn't been the only one preparing, however.
Gotham's Dark Knight, the Batman, has found multiple suitable 'heroes' as a defence for the Earth- New York's golden hero, Spider-Man, the underground terror Rorschach, Batman's protégé Nightwing, and of course, the HellSpawn Al Simmons.
As the threat of the Corps looms, Batman desperately looks to unite all of these heroes, and fight back.
If not, the Earth is as good as lost.
[This Book will not make sense if you do not read the other four books]