(8/7/2020) Permanents put onto the battlefield due to Karn's ability will have been under the starting controller's control continuously since the beginning of that player's first turn
Confirming the card number and treatment before looking at any price removes most of that error
Essentially, the designers have taken a few of the highlight cards from select sets and given them alternate art by notable Japanese artists, making them unique, rare alternatives to their normal versions
That means you can just delete a creature your opponent controls even if youre tapped out of mana
If, during your declare attackers step, Ursine Monstrosity is tapped, is affected by a spell or ability that says it can't attack, or hasn't been under your control continuously since your turn began (and doesn't have haste), then it doesn't attack
The Blue-Red Limited Archetype: Instants/Sorceries & Adventures Blue and red mana combine to make "The Sorcerer's Apprentice," a spell-heavy archetype that also makes good use of adventures