Its a Commander-designed mechanic that controls the flow of combat, disrupts enemy plans, and keeps heat off your back while your opponents deal with each other
The more different types of attackers a deck has, the harder it becomes to get the right energy at the right moment
My personal favorite is still the Mystical Archive because it felt good in Limited formats (mainly being answers, not threats, but still interesting) and some spicy old cards like Channel included
More details on Jungle and Cosmos Holofoil In Jungle, there are 16 Masters, where each Master has at least 2 variants with the Cosmos Holofoil pattern, i.e
Chase Cards: Crystal Charizard, Crystal Celebi, Crystal Ho-Oh, Umbreon