[confirmed]Tezzeret, Agent of Bolas & Master of Etherium

[HarlequinCasts]

Describe the Bug:
If, for example, a 4/4 Master of Etherium is targeted by Tezzeret, Agent of Bolas 's -1 ability, the Master of Etherium incorrectly becomes a 9/9

Tezzeret replaces Master of Etherium's power and toughness with 5/5. The master of Etherium does not get +1/+1 from each artifact, rather its power and toughness simply is that number. Hence the Tezzeret ability should overwrite it.

This layering type effect may be too tricky, or perhaps this is a simple bug like maybe Tezzeret is just giving +5/+5 instead of setting p/t.

Which card did behave improperly ?
Tezzeret, Agent of Bolas & Master of Etherium

Which update are you using?(date,name)Which type(Duel,Gauntlet,Sealed Deck)
Journey into Nyx v1 5/2014

What exactly should be the correct behavior/interaction ?
Master of Etherium becomes a 5/5 artifact creature regardless of how many artifacts you control.

Are any other cards possibly affected by this bug ?
NA

[Korath]

No creature with characteristic-setting abilities are going to interact well with anything directly setting power and toughness; the former are all coded similarly to "Master of Etherium (0/0) gets +1/+1 for each artifact you control", and the latter as "Target creature gets +X/+Y, where X and Y are chosen to make the numbers right if the creature doesn't have anything else affecting it at the moment". I'm fairly sure there's an open bug about Snakeform or Humility or one of the similar cards (about the power/toughness setting part, not the losing abilities part); both halves of this bug are variants of that same problem.