mana is spent to fuel other cards, such as summoned creatures, enchantments, or spells that inflict direct damage
If your opponent tries to kill Bloodghast the old-fashioned way, it wont be long until they have to deal with the creature again
Royal Treatment isn't entirely a one-off effect since it grants the Royal role, with ward 1 being appreciable protection after the fact and +1/+1 being a fine boost for any trampling threat
Put that card onto the battlefield tapped and attacking, and the rest on the bottom of your library in a random order
Knights of San dOria Compared to Akromas Will, Ranger-Captain of Eos is rather tame
Later on, bringing them back is great value, as they can instead search out a more expensive and impactful piece of equipment like a Sword of Feast and Famine, or a Helm of the Host