Forum:Koa'ki Meiru Guardian & Rai-oh

1. Can Koa'ki Meiru Guardian and Thunder King Rai-oh tribute themselves when Macro Cosmo/Dimensional Fissure is on the field to negate monster effect or a special summon?

2. Can Koa'ki Meiru Guardian negate effects that activate in the graveyard such as sangan, destiny hero malicious or Mezuki?

3. How come Thunder King Rai-oh can not negate Mezuki's effect to special summon? If so, is it true that he cannot negate stardust dragon as well?

Thanks