OK, in pvp against an FB that used mana freeze - or whatever they call that debuff - I have used this with some success. It's not 'sporting' but hell, I do not feel like fighting with no mana.
Use the flee rate buff. Make sure you have space behind you. Use fadestep, followed by force kick, start combo, Lightning Slash, Storm Grind - then combo as normal.
You need to be fast, but the combination of fadestep with force kick means your char is moving really fast, that 2 second stun is enough to get your combo started if he has not managed to retarget, so it is not that easy to re-target then, and again while casting LS you are moving at a rate which make targeting you not the easiest thing, and with luck SG knocks the opponent down, giving you some time continue with combo.
Yes, this depends on the opponent not being that good (but would a skilled player be using Mana Freeze in pvp?) and some luck is required, but it has worked for me.