Forum:Trust Guardian Confusion

I'm a bit confused by the ruling on "Trust Guardian" it states:-

"Trust Guardian’s effect is mandatory. It protects the Synchro Monster even if it can’t lose 400 ATK and DEF. The ATK and DEF will remain reduced for as long as the Synchro Monster is face-up on the field."

Does this mean that the synchro monster cannot be destroyed even if that monsters ATK and DEF are already 0? And if it's used to summon "Stardust Dragon" would the effect of "Trust Guardian" still be in effect if "Stardust" sacrifices itself for it's effect?

thanks 2.125.61.185 (talk) 19:15, July 3, 2011 (UTC)