its block dmg not block debuff or block everything thats aimed against ...

Are you refering toenemies with Block damage in PvE content where you cant kill them because your team has some kind of TM reduction that you inevitably have to use therefore not letting enemy take a turn and then have the block damage buff expire?

You need a Buff Stripper,. buff stealer or Buff duration decreasing champion. I know that it can be annoying when trying to auto run something and then look up at screen to see your at 14 minutes play time and still on round 1. 

And if they made Block damage with TM reduction immunity it would probably annihilate whatever system you have it running on lol.