There are still a lot of common abilities that are brand-new to me scry, flash, lifelink, this thing where I earn the citys blessing, legendary cards that have four different potential abilities but most of it gets helpfully defined simply by right-clicking on a card
But what are the mechanics you can expect
Archaeomancers Map is another piece that ensures you hit the land drops, but crucially unlike Gift of Estates, helps you to catch up too
But in templating the cards ability as splice onto arcane, Wizards teased the potential to splice onto other things
All this is to say, the expected value of the rare slot likely looked a lot better on paper before the set was spoiled than it does now
It doesnt copy whether that creature is tapped or untapped, whether it has any counters on it or Auras and Equipment attached to it, or any non-copy effects that have changed its power, toughness, types, color, and so on