An Aura put onto the battlefield this way doesnt target anything (so it could be attached to an opponents permanent with hexproof, for example), but the Auras enchant ability restricts what it can be attached to
For casual games this means pretty much any card you own that isnt currently part of the game
You obviously wont want to proliferate your own battles since you want to remove them as quickly as possible, but you can always proliferate your opponents battles to drag them out as much as possible
However, both formats may exert influence over one another
MTG Arena Announcements, March 23, 2022 State of the Game Alchemy: Kamigawa Last week, Jay Parker and Megan O'Malley gave us a look at the new 30-card set, improvements coming to MTG Arena , and lots more
Light Test The light test is one of the most common and most important tests to know and it is easy to perform