pvp depends on what your formation is if your more focused on a 3-1-1 formation then ashishiso jizo is your best friend not to mention a starting hit for 12% of your attack then another 12% every round for 3 rounds kinda stacks up well as well for 36% of your overall attack just from the dot damage. ashishiso jizo is also good if your van is offensive as well and your supports are stunners. I say this because i used starrk with a all in speed yoru and gin the 12% damage reduction from ashishiso jizo does wonders compared to the none existent defense buffs from Kazeshini.
Each zan has its own style though Kazeshini is for a fast fight while ashishiso jizo is for a more drawn out fight.
Kazeshini also has his advantages though like the boost to damage rate and assaulter speed at the cost of making your van less tanky.
Theses are just my thoughts though.
gilix3 replied at 2015-4-20 20:33
and what about when you get "ashisogi jizo" and "kokujo tengen myo"? there are both free too
ashishiso jizo can be handy for PVP vs certain opponents. (not a pve type zanpakuto)
Kokujo tengen can be handy for some Soul Hollow maps.. but nrmly zabimaru should do the trick (or p2w zanpakuto's)