pokemon booster pack contents - Mega Evolution: Ascended Heroes (Each booster pack contains 10 game cards Pokémon TCG: Mega Evolution 1

Let's look at what this means for new cards in the set

Belligerent Yearling's ability overwrites any previous effects that set its power, including previous instances of that ability

Whenever you copy a mutate creature while it's on the stack, like with Volo's ability, the entire chain of mutate abilities will begin again when your copy resolves, giving you so much more value than normal

Selling takes time, costs money (platform fees can exceed 13%), and depends on market conditions you cannot control

Your second best option is to use Abyss Seeking to fill your Lost Zone as quickly as possible to start threatening Lost Mine