Last weekend, it was one of the two leaked devices from Sony. Earlier thru their @sonyxperia Twitter page, they made it official
Sony Xperia C5 Ultra has Android 5.0 Lollipop with 64-bit 1.7 GHz Mediatek MT6752 octa-core processor, LTE (not available in all markets), 6 inch IPS FHD display, 13 MP AF Exmor RS rear cam with LED flash, 13 MP Exmor RS front cam with selfie flash, 2 GB RAM, 16 GB ROM, Bluetooth 4.1, NFC, GLONASS, WiFi, micro USB, FM Radio, micro SD expandable up to 200 GB and 2,930 mAh battery. This was made official thru the official Sony Mobile website
It's quite refreshing that Sony has put up phones with Mediatek processor (check the other blog post). No official info yet on pricing and release date.