If an adventurer card ends up in exile for any other reason than by exiling itself while resolving, it won't give you permission to play it with its primary characteristics
That said, Rampaging Ferocidon is now just another three-drop in a sea of good red three-drops, and you could just as easily end up wanting Goblin Rabblemaster, Goblin Chainwhirler, or no three-drops at all depending on how you build your red decks
Really, having great energy-generating creatures like Whirler Virtuoso or Roil Cartographer in your starting hand along with three Plains feels like cruel punishment from the Magic gods
Ouroboroid Considering Bristly Bill, Spine Sower has shot up in price to like $70, it doesn't surprise me at all that this 1/3 for four mana is preselling for $20-$30
But for its first half, its a seven-mana way to make everyone get rid of their hand (and graveyard, if someones shenanigans are bothering you) without replacement