I Have a Cultivation Island in the Apocalypse

When the apocalypse arrives, 50% of the world's humans, animals, other creatures, insects, plants, and marine life mutate. The humans who survive are horrified to discover that every mutated organism keeps evolving, while they themselves remain unchanged! As the mutated creatures slaughter humanity one step at a time, are humans really going to be wiped out? No! Nine thousand nine hundred and ninety-nine ancient legacy trees rise from the world's oceans. They hold the angels, magic, and warriors of the West; immortal cultivation, Daoist practice, and ancient martial arts of the East; and shamans, Brahmins, Buddhas, sorcerers, and more from other regions... They stand silently upon the waves, waiting for the chosen to receive their legacies and lead humanity's survivors into one epic battle after another against the mutated creatures!