Octoberland by A.A. Attanasio is free to download on Amazon (US, ES). This is the product description:
A Manhattan coven, Octoberland, weaves ancient black magic to preserve the life of its 7,000-year-old leader, Nox. The sorcerer staves off death by leaching years from his followers’ blood. But Nox’s reckless search for eternal youth has opened the gate to — Irth.
From this alien world of wizards, witch queens, and blacker magic yet, goblins invade Earth! Warped, revolting creatures from a higher world beyond the World’s End, they inflict bloody carnage on the Dominions, using trolls and basilisks as their weapons.