The latest trend that has been seen with these cards is getting Disney Parks Character Autographs on them, and that is just awesome
It can be a Common, Uncommon, or Rare card where the entire card is holographic except for the art box
The error seems to be in the fact that some of those reverse holos were supposed to be common printed cards, but the manufacturer packaged them wrong
Your attackers will have to be Creatures that youve cast previously, as a condition called summoning sickness prevents creatures from being tapped for one turn
You don't want to base too much around what could happen, but it's a good element to factor in
It protects your creatures from being countered and gives them haste or +1/+1 counters, all at 3cmc