Non team-vs-team featured game modes?

I'm not sure how many people in this community started their 'moba' days in Warcraft 3, but that's where I did. One of the custom maps I played had a typical moba game mode but also 5 others. One of which was Hero Defense. Just waves and waves of monsters assaulting your base, getting progressively harder, new units with new abilities appearing so often...

Your recent Slayer champion skins made me think zombies are overdone, there's so many games of zombie killing out there. But that doesn't make it any less fun, and who wouldn't want to defend their nexus from a horde of zombies and zombie boss units using their favorite champions. Co-op survival that might actually be challenging?

Just an idea to throw out there for your next harrowing maybe? A featured game mode that is more than just typical base vs base with a twist.