This isnt to say each set had dozens of these cards
They invaded Dominaria because we wanted jeopardy, and, at the time, Dominaria was the home of Magic . The fact that this interdimensional invasion forced all the various factions and colors of Magic to unite against a common enemy fit nicely with Invasion's multicolored theme, but, apparently, that was a happy accident. Back then, the narrative and card design teams didnt work together that closely, something thats changed significantly in the decades since
Creatures like Looter il-Kor, Putrid Imp, Oona's Prowler, and Fauna Shaman can first get your reanimation target in the graveyard, and then sacrifice itself to your Recurring Nightmare to complete the combo
I guess that's hard to represent so they just kind of went for him being a stand up guy (which he is), and a leader
By the time you have five mana to cast it, you will likely need more cards in hand