Why do some chromas have extra names and some don't?

For example, we've got: Darius Forge, Blitzcrank Steel, Lucian prime, Zac Sweet and Bard bloom for base champs.

Even certain skin chromas got given names: Dragonslayer Vayne Chaos, Rocketgirl Tristana Punk, Dragonfist Lee sin Duel.

Now we've got chromas with no extra names attached.

INCONSISTENCY RIOT. I WANT PEOPLE TO NOTICE MY DUNKMASTER DARIUS.