Kingu Wa Kingu Da

Oh how the mighty have fallen, off the competitive scene.

It's no surprise, really. "Red Dragon Archfiend" is the ace-in-the-hole against defense position monsters that replace themselves when destroyed in battle, but the effective methods to summon a level 8 Synchro in Main Phase 1 have been reduced on account of the Destiny Hero engine being rendered more or less unplayable by the ban list. RDA doesn't do anything during your opponent's turn, so summoning it in Main Phase 2 with "Flamvell Firedog" and "Flamvell Magician" isn't worth doing. On top of this, most defense position monsters that are running around are either granted their effects by flip, or by destruction in general, so RDA can't play around them like it can "Mystic Tomato" and friends. RDA's drawback during the End Phase is ever present and prevents a lot of optimal plays from being made as well.

It is, of course, still a very large beater - the largest that "Debris Dragon" can access, so RDA will still find a home at 1 in the decks that utilize Debris, and perhaps other obscure decks that frequently Synchro Summon level 8 monsters and not many others. Being DARK, it offers tricks with "Deck Devastation Virus" and even "Eradicator Epidemic Virus" if one can be so inclined to use such a thing. RDA can be revived with "Red-Eyes Darkness Metal Dragon" all the same as its brethren, and it's definitely worth playing on rare occasions in those dragon-based decks out of synergy alone.

Let's hope it gets an evolution that's worth using. Being inferior to Stardust on all fronts for the rest of its life would be terrible.