Its a mechanic that turns on once a card enables it and can be taken by dealing combat damage to the player with initiative, much like monarch
Many of your gold and gem purchases go through the MTG Arena store which is one of the main ways you can get cards in MTGA
Im not sure, threat them more like A tier
, Tap an untapped Rebel you control: Return this card from your graveyard to the battlefield tapped
Ojer Kaslem, Deepest Growth Ojer Kaslem, Deepest Growth has trample to help get combat damage through and is able to get lands in addition to creatures, which is great for this reasonably costed legendary god
While I had positive experiences playing with Key to the Archive (and then later against it, once I knew its possibility space), my experience overall has made me less interested in playing with more draft/spellbook cards