Disclaimer: Flashtool is a third-party tool. Modifying your phone's software voids warranties and carries inherent risks. This post is for educational and nostalgic purposes only.
Before fastboot was user-friendly, there was a Java-based savior for Sony smartphones. If you have been in the Android modding scene for more than a decade, certain version numbers trigger an immediate wave of nostalgia. v0.8.6.0 is one of them.
While modern Flashtool (by Androxyde) has evolved significantly, the 0.8.6.0 release represents a sweet spot in history. It was mature enough to be rock-stable, yet old enough to still support the legendary Sony Ericsson Xperia arc, the Xperia Play, and the early Xperia S series.