Could it be… white spells?
It’s common for the art of a creature-affecting card to depict a creature aligned with the spell’s enemy colors as the victim of the spell. Echoing Decay depicts white-aligned leonin warriors getting whacked, while Awe Strike shows a black-aligned nim zombie taking the brunt.
In Ravnica, enemy colors means rival guilds. And black-red Rakdos’s natural enemy is the color white.
We’ve already seen that Harrier Griffin shows a Rakdos warrior getting munched by the eponymous griffin. But there are more Rakdos cameos.
Ravnica’s Devouring Light shows a minor Rakdos demon shriveling under the holy blast of energy of the spell, for example. See the characteristic design of the skull armor, and the multiple horns?

Devouring Light art by Pete Venters
Dissension’s splashy removal spell Condemn shows a burly Rakdos cultist humbled by the swift judgment of an Azorius ruling.

Condemn art by Daren Bader
There’s even a touch of Rakdos showing up in Plumes of Peace. As artist Justin Sweet shows, it’s tough to swing your bloodstained sword—or even see your target—with all those irritating doves around. Blasted lawmages!