It allows you to look at the top of your deck at any time, and you can play the top card of your library if it's a land and an opponent has more lands in play than you
But I just turned it on this morning, and now it tells me i'm offline
A last thing to note is that since Valki allows you to see all of your opponents' hands, he lets you know when it's "safe" to cast himself as you become aware of whether people have removal in hand
Her ability is incredibly powerful, but even playing her must be carefully timed
In your average Limited game, how have you not won the game normally if youve dealt combat damage to your opponent over 10 times
You can also create some lines of play with infinite Dualcaster Mage, Archaeomancer, or Izzet Chronarch tokens that have haste for an attacker-based victory, or simply cast Inalla after youre done making tokens then ping your opponents to death 7 life at a time