It’s 90+. Krieg set is technically unrelated, you can even keep playing with Forcewave while running Krieg Set, just gonna need another belt to convert aether (Stoneplate Waistguard, that aether conversion on it wasn’t a thing back when I made the guide).
The condition to switch is actually getting a good enough Celestial Halberd. The location it drops in is quite a detour, so I’m not switching before 90, even though it’s possible.