These cards are not just powerful tools but pieces of the games art history
You build up your tokens, but need to give stuff to opponents to do so, and as long as you avoid giving them cards that cause them to lose, you'll get plenty of 5-star reviews
Based on the latest market prices tracked on TCG Stacked, Vivi's Persistence is worth about $38.12 USD for a regular copy and $37.65 USD for a foil copy
For example, the effects of a Heroic Intervention will cease when you activate Obeka, as the card explicitly says, until end of turn
Changes You Can Make The most obvious change you can make to this Gruul Landfall deck is to add more protection spells : spells that deal damage to potential blockers, add hexproof to your creatures, or, even better, make them indestructible