It spreads +1/+1 counters around your other legends or those your opponents control, but if one of those buffed-up creatures dies, you draw cards equal to the number of counters it had, though at the cost of 2 life per card
This does not necessarily make those decks bad, as their power level can overcome this flaw if the combo it provides is simple enough to win games when it opens optimally
(I was briefly running Haunted CloakHaunted Cloak before I realized that Ragnaraok already has all three keywords that the Cloak grants.) We'll take some flying from Cliffhaven KitesailCliffhaven Kitesail, some double strike from Brass KnucklesBrass Knuckles, and some shroud from Whispersilk CloakWhispersilk Cloak
Since it is a new subtype, however, vehicles do not have the same amount of support that equipment has
The card is selling for almost $400 right now in paper, and fifteen cents on MTGO
Some of the most popular formats include Standard, Modern, Legacy, and Commander