My Templar can withstand far greater amounts of poisoning than Chryos' radioactive beam can provide...Genetically engineered demon-infused super mutant? Naturally
Now, as for the ultimate attack, well, not if we find a way to reverse it. Like the *ahem* *looks at HahiHa* scientific minds between us know, the Black Hole basically is a burned out star, the gravity of which is so strong, it does not even let light escape it. Now, to make such a thing, you need a great amount of mass. Not only that, you need to compress it too, at an impossibly small size. It has been theorized that for Earth to become a Black Hole, the whole mass it currently has, including the people, the buildings, everything on top of it would have to be compressed at the size of a golf ball.
Now, what's my point? Where do these creatures get that mass and how do they compress it? If we find out, maybe we can stop them, but, assuming no strong gravity field is in play yet (I don't feel being pulled apart violently, do you?), then our fellows must be first gathering all the mass they need, and then planning to compress it.
So, to sum up, we have quite some time to stop that from happening. My first thought is that somehow they are draining mass from the void, their dimension, through portals. waS is most definitely going to protect the Sol as it prepares the black hole so we need to stop it first.