Perhaps the skull is none other than Mufasa's, as the card's title, "Scar - Finally King", might suggest
Blood Tokens are artifacts that for one-generic mana, can be tapped and sacrificed to discard a card and then draw one back giving a madness opportunity and extra card advantage for one mana
At the beginning of your upkeep, you add two counters to Descent into Avernus, deal damage to all players, yourself included, equal to the number of counters on it, and everyone creates that many Treasure Tokens
Yes, monarch triggers at your end step and can change designations when combat damage is dealt
Basically, it doubles your chances with every coin flip, and thats the kind of thing thats going to supercharge your deck, and make it slightly less about luck, and slightly more about winning a lot
That damage can then be upped via Grab Your Sword or just using Tinker Bell to attack and spread damage via her Puny Pirate ability, assuming shes been shifted via Morph