Mythic Mania 2 (not called "Myth Harder," much to my dismay) is a new pair of expansion books for Pathfinder that brings even more mythic material to your games. There's no such thing as too many options for your games, if you ask me, so having some more books has got to be a good thing. The new tomes are up on Kickstarter now.
From the campaign:
When the mythic rules for Pathfinder debuted five years ago, Legendary Games unleashed an incredible project - MYTHIC MANIA - teaming up with Kobold Press, Rogue Genius Games, and Dreamscarred Press to bring you three comprehensive expansion volumes, the Mythic Hero's Handbook, Mythic Monster Manual, and Mythic Spell Compendium. Altogether, we gave you over 900 pages of incredible material to blow the lid off your Pathfinder campaign with literally thousands of mythic feats, spells, monsters, magic items, psionic powers, class features, path abilities, skills, traps, curses, and more to make your campaign dynamic and cinematic in ways it never was before. It was amazing and we thank everyone who made it possible.
Since then we've continued creating even more magnificent mythic material, bringing you even more paths, monsters, magic, and more from around the world, and the time has come at last to close the circle and bring it all home to you. Welcome to MYTHIC MANIA II !!!
Mythic Mania II encompasses two books rather than three, and incorporates mythic material for hardbacks like the Advanced Class Guide, Forest Kingdom Campaign Compendium, Horror Adventures, Occult Adventures, Ultimate Intrigue, and Ultimate Wilderness, as well as potentially adding in more material from the Adventurer’s Guide, Monster Codex, Planar Adventures, Villain Codex, Book of the Damned, Pirate Campaign Compendium, and more!
The campaign's about 2x funded with still 26 days left to go.