We're going to do a thorough analysis of each deck, highlighting its goals and how well it accomplishes them, check out its deckbuilding fundamentals, identify its strongest and weakest cards, then use all that information to create an optimized $50 upgrade path
Creeping Chill is typically milled away, and when that happens, it's efficient, like a Lightning Helix to the opponent
According to Gavin Verhey, one of Magics principal designers at Wizards of the Coast, melding cards is meant to be a challenge
It doesn't copy whether that creature is tapped or untapped, whether it has any counters on it or Auras attached to it, or any non-copy effects that have changed its power, toughness, types, color, or so on
That's how I would build my Rex Nebula brew