User blog comment:Mckrongs/Monster Hunter 4 for the Nintendo 3DS/@comment-184.38.6.146-20121214230446/@comment-4212769-20121216110320

I'm very sure it doesn't revive the Tigrex but only faints the Tigrex to take over control.

Let's imagine the "virus" or whatever it is in the end as a parasite, what most virusses are but without intelligence. We say this "virus" is intelligent enough to notice when the monster is near death. As it still needs the host to multiply and/or for shelter it needs to take over to make sure the host survives and it can go on with its actions in it. But to control it effectively it needs to faint out the mind of the monster. This process is the death animation we see. But then the virus takes over and tries to get rid of the attacker.

That's I think the most probable and plausible explanation I can come up. Reviving is just too much, so I'll hold on to this theory.