While Square Enix has its own Luminous Engine for future games development, that doesn't mean the publisher won't use other tools to make the best games possible.
Speaking of which, it seems the publisher is on pace to be one of the forerunners in the next-gen race, as Epic Games has announced that Square Enix is the first publisher to license Unreal Engine 4 for multiple upcoming games.
This agreement between the two companies mean that Square Enix will be developing and releasing games built on the Unreal Engine 4. However, more in-depth details has not been released. Also of note, the agreement isn't just for Unreal Engine 4 exclusively, as the multi-game deal also extends to today's oft-used Unreal Engine 3.
Taka Kawasaki, territory manager of Epic Games Japan, had this to say in a press statement:
Epic has a strong relationship with Square Enix, and it’s an honor to provide their creative and technical talent with the best game technology available for licensing…We look forward to supporting their developers with world-class tools for years to come.
The most recent Square Enix game to use Unreal Engine 3 is the iNis-developed mobile game Demon's Score both for iOS and Android platforms.
Does this mean Square Enix is dropping its Luminous Engine? I highly doubt that, but them using Unreal Engine 4 for multiple games confirms one thing: they're hard at work on next-gen titles! Not that should be a surprise, but at least we know what engine they'll be using, no?