For Challenge # 111, and yet another creature that become Legendary by default. I'm not really sure if this guy is printable, considering his two abilities won't interact in a way most players think they will (I guess, he mostly flickers your stuff. That being the case, the activation might be too high? He does protect himself...)

Oh, interesting idea, though may be too Johnny/Melvin, I'm not sure. Most of the time, this is just "flicker", so most people will be disappointed (and might get the message more clearly if instead of "legendary" it just said "3U: sacrifice target creature you control, put a copy of it OTB").

The most promising avenue of abuse might be sac effects. Composite Golem gives infinite mana, but that's not really too good for two six-cost creatures. And you can put infinite copy-effects on the stack, but unfortunately, I think there's no way to kill this before they resolve without another effect.