hidden tenryu 30 sec buff mechanic?

so ive been doing gold arena runs and noticed something...
enemies on normal have only 550k hp so ive been using zantei since i can keep up with mana with ampr and timing isnt an issue as you are bombarded with aoes all the time. ive never even used tenryu but what suprises me is that i will sometimes see the 30 sec tenryu buff active.

so what caused this? is there a hidden mechanic?

 

It's not a hidden mechanic, it's how tenryu works. Basically, Every consecutive tenryu during the buff deals more damage. the buff duration can be extended by meeting certain conditions, a.k.a Use Zantei and get hit when tenryu is active, or Magadachi and NOT get hit with tenryu buff is active.

 

i know how tenryu works but i NEVER used tenryu at that time. i was simply spamming zantei ONLY and the tenryu 30 sec buff just appeared. it just appeared even if i wasnt using tenryu so im not under the 10 sec tenryu buff. i dont know whats causing this as aoes are flying all over on gold arena and im just in the middle doing zantei

 

uhh... idk. I'm not a katana expert.

 

Tenryu buff should not activate by zantei. Clear indication is if zantei does armor break it is the regular one not zannou so yes its most probably a bug.