My question is when serene master becomes a 15/2 and Rhino become a 0/15, does rhino's passive ability then give him +10/+10 again (making him a 10/15), or does it stay a 0/15 and die? (I guess it would be the same as eidolon of countless battles. But there were no rulings on that either)
Thanks for any help, I can normally google this stuff, but no one really talks about serene master.
If an effect requires information from the game (such as the number of creatures on the battlefield), the answer is determined only once, when the effect is applied. If the effect requires information from a specific object, including the source of the ability itself, the effect uses the current information of that object if it’s in the public zone it was expected to be in; if it’s no longer in that zone, or if the effect has moved it from a public zone to a hidden zone, the effect uses the object’s last known information. See rule 112.7a. If an ability states that an object does something, it’s the object as it exists—or as it most recently existed—that does it, not the ability.