Wizards of the Coast took a technique used in its Japanese trading card game Duel Masters and printed text on both sides of the card to represent people transforming into monsters and back again (something that happens alarmingly regularly in Innistrad)
Two of each rare, one of each mythic
Sheldon Menery, the godfather of Commander and head of the RC, even said that the card is too generically good and pleaded with Wizards to Please never print this card (Wizards apparently asks the RC for input during card design)
And second, youre not forced into toughness-matters here, since you could just as easily build around high-power, low-toughness creatures instead, which would be a very interesting direction to take Doran
This may be overkill sometimes since some cards were only ever printed in one or two sets , and sometimes those sets have different borders