For the most part, you can sit with one of these cards on the battlefield for most of the game and wait for them to cast a Past in Flames before going to exile their graveyard, but if the Past in Flames is in the graveyard already, you may want to preemptively go for it
In Brethren of Ash, you and your friends will dodge dangers and escape the encroaching flames as you race against time to uncover the identities of the campaigns namesake, the members of the Brethren of Ash, and stop whatever their goal may be
If enough -1/-1 counters are put on Hei Bai at the same time to make his toughness 0 or less, his last ability will see all of the +1/+1 counters he had when he left the battlefield as well as the -1/-1 counters he had, and an equal number of each of those types of counters (plus any other applicable counters) will be put onto the target creature
Also, protect your cards, as their price will directly depend on the card's condition
their opponent cant do anything against them anyway