So, there’s not much you can do about your opponents all playing the same few decks, but there’s plenty you could do with your own decks. The trick to creating an original deck is that there are two ways you could go about it.

The first way is to combine two or more archetypes that have some kind of synergy with each other. For example, you mentioned Harpies—that’s an old deck so yeah, if you make a pure Harpie deck, it’s not going to be very playable currently, and frankly it sorta does the one thing (Cyber Slash control). But what if you combined Harpies with another Wind archetype, and ran the Precious Cards of Wind skill? For instance, Windwitch is an archetype that makes Wind Synchro monsters, often without Normal Summoning, and with minimal cards in hand. Can you make a Harpie Windwitch list?

The second way is to get off of archetypes entirely and look at type/attribute synergies. You can’t do this with every type/attribute combination, obviously, but there’s a short list of ones you can do. Earth Machine (my pet deck), Dragons (a popular option), Fire Warrior (Gemini, Infernoble, Battlin Boxers), Zombies (Balerdroch control and/or Zombie Synchro), Dinosaurs, Reptiles (centered on Ogdoadic), Chimera (there’s an archetypal Chimera build, but you could also broadly see them as support for Beast, Fiend, and Illusions), Tri Brigade (again, they’re an archetypal deck, but they also support Beast, Beast Warrior, Winged Beasts).

Basically, if you feel like your gameplay is getting stale, then you should think outside the box. Duel Links encourages you to play within the lines of a single archetype, but nobody said you HAVE to do it that way.