Depending on your dueling we can simplify the deck ... I think we can make this strategy more consistent. dueling with this i had concerns about dealing with his Macro Cosmos and Gravekeeper match-ups: those are probably challenges that should be overcome with the side deck, and not so much Main Deck issues (those match-ups are pretty rare). also that i felt the strategy was predictable, which is one of the big downfalls of more conventional Rock Stun builds; they're pretty linear, and since they open at a fairly slow pace alot of opponents are able to stay one step ahead and just dominate you.
I think adding more consistency and more speed is the best possible answer. The Stun element becomes far less predictable once the graveyard is loaded and you open up a wider range of options. On top of that, you want to get to Exterio as fast as possible because it takes multiple cards to unleash. In a simplified game scenario where each duelist controls very few cards, you can't get an Exterio combo going - and even if you do, you could lose to a big topdeck. Exterio works best in complicated game situations, where you can protect it more easily and lock down more of your opponent's cards to create a big advantage. Faster is better here, for a number of reasons.
I know what I want to add, so the main challenge for this fix was figuring out what to swap out. One Block Golem was an easy choice: it's an incredibly powerful card, but seeing it dead in the early game is a nail in what fast becomes your coffin. We can't afford that. In addition, with a deck like Geargia kicking around that punishes you every turn for being passive, Giant Rat is just too slow. Searching for your Tuners is useful, but that's largely all Giant Rat accomplished and I think there are better ways of doing that.
With so much negation going on and a need for more space, the one copy of Mystical Space Typhoon gets bounced to the Side Deck. One Compulsory Evacuation Device gets cut to make more room, and the two Pot of Duality are nixed because I actually found them to be an awkward fit in the mid and late game, where Special Summoning becomes so much more important. Again, we're going to be substituting the consistency Tek found through draw filtering, by building our graveyard faster and drawing more cards.
How are we going to do that? Double Card Trooper. Trooper is one of the best cards in the game when it comes to milling stuff. It fits the Earth theme we're working with; it gets better and better as Thunder King Rai-Oh becomes more popular; and it's a nice beatstick that adds some draw acceleration to the strategy. It's not a Rock-type, but we only dropped one other Rock monster from the lineup.
We'll be replacing that one missing Rock monster with another: Morphing Jar. This classic flip effect can load your graveyard, get you some quick card advantage, and help you draw to the cards you need. Since it hasn't seen much competitive play over the past few years the Jar can take your opponents by surprise, and it fits nicely with your tendency to set multiple back row cards. Remember, though we're not running Starlight Road, we are packing a number of negation cards that can ward off Heavy Storm.
I'm going to add a Mind Control to get over big, problematic monsters and create more Rank 4 Xyz Plays. This may be a metagame call for you - you might decide that you like a defensive trap card more, so play with this slot to find what's best for your style.
Finally, when I go for that Naturia Exterio play I want to know it's going to stick. Two copies of Trap Stun will help you make big pushes against your opponent in the early game, while also protecting your Exterio combos in the mid and late game. Trap Stun's a card I've been tinkering around with a fair bit in the new format: it's really useful here, where it can stop Solemn Warning from shutting down your biggest moves, and prevent Bottomless Trap Hole from banishing monsters you want yarded for later. Here's a quick run-down of all the changes I made:
