The density of Madness cards means that the deck is effectively a 60-card deck, increasing its consistency
This allows its caster to force an opponent to waste a kill spell and add a layer of protection to their creatures
Battle for Zendikar was the first set to have an explicit lifegain mechanical theme without a keyword: Serene Steward and Cliffhaven Vampire formed the basis of the archetype, enabled by cards like Vampire Envoy and Stone Haven Medic
The card, if you want to cast it from your hand, actually costs UUU and not UU
Keep in mind that the codes for older sets, like Throne of Eldraine, Theros: Beyond Death, and Ikoria: Lair of Behemoths, will become invalid at some point in the future
Though Kamahl is now long dead, the order of Kamahlite druids was established in the Krosan Forest in honor of his actions and memory