Buus reached full power" super soul analysis and it's amazing power with fighting sun seeing how fighting sun is stronger then b.r.f.p I would say it's a 50% or so damage boost :
Hacker, be on the look out for them : r/dbxv
Ki Mixer: A Modified Darkness Mixer for General Usage (Including CACs) – Xenoverse Mods
OVER 40+ NEW CHARACTERS!!!! DRAGONBALL XENOVERSE 2 MEGA MOD PACK Gameplay!NEW SLOTS! - Vídeo Dailymotion
Darkness Mixer on a CaC? How do I get it? : r/dbxv