>>10879860>>10880178>>10880228>>10880248Coming from MTG this is all obvious. "Can't be targeted by" and "unaffected by the effect of" are two very different things, and one is much more powerful than the other. You can't Lightning Bolt something that "can't be targeted", but you can still Flame Wave it and kill it. If it is "invulnerable", though, both Lightning Bolt and Flame Wave could hit it, but it is unaffected by taking the 4 damage either way.
Likewise here. The ruling that Madolche doesn't target (in my opinion, a bizarre and broken ruling) is irrelevant, it concerns whether you can use the ability on him. If the ruling was that Maldoche's ability DOES target, Masterpeace doesn't have any ability making him untargetable, so you could still use the ability on him. Either way the ability gets used on him, and then he is unaffected by it.