Unlike something like Starting Town, you cant turn off the life loss at any point unless you just stop using it
The way it works is simple: if your opponent has a Pokmon on their bench that has taken damage, you can swap it to the active slot
Finally, because he can make many spells and abilities free, he can be the third card in numerous infinite combos, like Carrion Feeder and Gravecrawler, Necrotic Ooze with Asmodeus, the Archfiend in your graveyard, or even just K'rrik and Blood Celebrant, which essentially makes a free mana of any one color for each three life you pay
A reasonable approximation of the expected power of gold cards is that your 2nd colour of mana adds about a 1/3rd of a mana, the 3rd colour adds 2/3rds of a mana and the fourth is a whole extra mana
Unlike typical abilities or keywords, Monarch is a designation a player can hold, transforming the flow of the game by introducing a high-reward, high-risk element to the multiplayer format