You must watch this first before watching Fate/Strange Fake but before that you must watch Fate/Zero and El-Meloi to get the reference or what the people are talking about. Don't expect for the anime to hold your hand or spoonfed you with information, you must also know a bit of both mythology and history to understand the servant's mannerism/actions. This studio really has doubled down that they can also make a good fate anime and of course Hiroyuki Sawano delivers another exceptional soundtrack.