Did Shusui really do this to get his mangekyo?

[00Rinne]

could it be possible he got it at a younger age than Godtachi did. Godtachi seen war at a young age & Shisui is older than Godtachi so it's possible he was in that war. Even if it was just a small part he played he still witness some war an that was enough for Shisui cause he seemed emotional and loyal to his pears.