The phrase "unique synthesis" refers to the creation or combination of something in a special and original way. It implies that the result is not like anything else and is one-of-a-kind. Full definition
Change occurs as each occasion becomes its own unique synthesis of its past and its relevant environment. (religion-online.org)
Because each actual occasion is its own unique synthesis of its past, each contributes its own actualization to the totality of reality. (religion-online.org)
Age of Storm received the award for Excellence in Online Games at the 2013 Korea Game Awards, a testament to the game's unique synthesis of RPG and strategy systems. (droidgamers.com)