Currently, Swords of Legends Online is using the inhouse engine named Havok Vision Engine.
Havok Vision Game Engine has been a discontinued Game Engine since 2014. It was first released in 2003 under the name Vision by Trinigy but later acquired by Havok and renamed Havok Vision Engine.
In fact, we have a whole list of game that uses this engine in the past including an all-time favourite Black Desert Online before it revamped into a Custom BDO Engine.
|wdt_ID||Game Title||Year||Windows PC||Platform|
|1||James Bond 007: From Russia with Love||2006||No||PS2, Xbox, GameCube|
|2||24: The Game||2006||No||PS2|
|3||50 Cent: Bulletproof||2005||No||PS2, Xbox|
|5||After Burner: Black Falcon||2007||No||PSP|
|7||Agent Hugo: Roborumble||2006||No||PS2|
|8||Age of Empires Online||2011||Yes|
|9||Age of Empires III||2005||Yes|
|10||Alan Wake||2010||Yes||Xbox 360|
|Game Title||Year||Windows PC||Platform|
While, Havok Vision Engine doesn’t look terrible, it is quite dated over the years, with Unreal Engine 4 giving it more of a “Realistic Look”.
Here is a video of a demonstration of the progress on migrating Swords of Legends Online from HVE into UR4.
My guesstimate is that we can expect a full migration into Unreal Engine 4 for Swords of Legends during early to mid 2022.
After all, Phantasy Online 2 English Global Release was April 14, 2020 and shortly after a year, they did a full migration into Unreal Engine 4 under the Phantasy Online 2 New Genesis Title, with NGS Beta already just earlier this month.
I believe we can expect something similar for Swords of Legends Online.