No matter how much people tell me Limited has changed, no one has really proven to me that two cards for free a turn reliably loses to someone without a Howling Mine
In the game, your leader card is always present on the board, so naturally, players want the shiniest and glossiest cards that they can afford to show their opponents
A Reddit thread, trying to gather all cards by community effort (Malco's answer provides a copy of that list) Basically, you would be able to tutor for any card from these lists, provided that the list is accurate
It chooses a single random card from either your or your opponents hand and shuffles it back to the deck
They are rarity, condition, age, and popularity
(You can't use this card if this is the last card in your hand.) You may play only 1 Supporter card during your turn