Fortunately for the Rakdos, their interest in the dark art of death has made them into top-notch mercenaries and assassins, which the other guilds are more than happy to take advantage of
If you lose the monarch ability, attacking with Aragorn helps you recover it
It focuses on sacrificing creatures for value, draining opponents life, and forcing painful decisions through Athreos ability
There aren't actually a ton of sacrifice outlets, with Ahriman and Phantom Train being the two cards you're likely to see in your pool
Now that includes inking a card like you normally would each turn but that also includes all the ways in which Sapphire can get extra ink on their turns including songs like One Jump Ahead and the new Friend Like Me, items like the Fishbone Quill, and the multitude of characters that mess with your inkwell like Belle, Strange But Special or even an opponent using a Hades, Infernal Schemer against you
That puts it a bit below Weapons, but its still very respectable for a Secret Lair