the kyube. Fusion bolt / ice beam / earth power / d claw @ life orb is fierce as hell, and breaks apart stall ive found. Switch advantage with mega lucario can break that down as well.
I think Expert Belt Genesect might be a better option because if it gets the Download and Expert Belt boost its Ice Beam is just as powerful as Kyureum's due to Download and Expert Belt replicate STAB and Life Orb respectively . It doesn't have the natural bulk unlike Kyureum, but it is not weak to Stealth Rock. This Genesect also lives off of the notorious reputation of Choice Scarf Genesect, and that grant it some more value beyond whatever its base stats, moves, and EVs are. Like Scarf Genesect, it switches out quite often and that behavior may lead your opponent to think it is Choiced, but it has the luxury to switch attacks, especially at a critical juncture, when your opponent thinks it is Choiced. Unlike Kyureum, Genesect can break Fairies, since it can hit with a STAB super-effective attack with a rather nifty effect; Genesect essential has a 240 base attack move (80 x 1.5 x 2) against them while Kyureum only has a 100 move, although this is somewhat mitigated by Kyureum's higher base attack and investment. Flamethrower (maybe for a physical variant Blaze Kick is acceptable if the calculations show it is a worthy addition, but this runs the risk of hitting into Rough Skin, Iron Barbs, and Rocky Helmet, not the mention the possibility of a miss that can cause a rage quit or coronary event) and Ice Beam are also
sin qua none, as Flamethrower hits Skarmory (on the special side) and Ferrothorn. and Ice Beam Gliscor, Hippowdon, and other ground types. However, Genesect's relatively low speed means diminished performance against offensive teams since it cannot even touch Landorus-I or Garchomp with its Ice Beam, even if your team features paralysis support. (I think Earth Power or Earthquake can KO it, since Lando-T did 90% with Earth Power on Lando-T on my Conkeldurr with about 200 HP Evs and no special Evs; Conkeldurr has naturally high bulk with some HP investment, while this Genesect has none.) X-Scissor is Genesect's strongest Bug physical STAB but due to its low base power and lack of coverage with Steel it is not optimal, and U-Turn is preferable since it can grab momentum against offensive teams. Extreme Speed provides some additional utility as a priority revenge killer (although this may give away that it is not Choiced), especially with max physical investment, and can give you a favorable endgame against teams whose Pokemon have low health.
The EVs are to be determined, although at least it should outspeed Jolly Dragonite and most Gliscor variants.
I am more interested in your elaboration because I perform poorly against stall teams. I wonder if the STAB physical Dragon, physical Electric, Special Earth, and STAB special Ice is a unique wall breaking permutation. Some calcs would be helpful. For Kyureum-B, electric is useful against Skarmory, Gyarados, Vaporeon, and Jellicent, and it can provide some neutral additional physical coverage against Steel. A STAB 80 base Dragon move doesn't seem that attractive though, since it only hits Dragons super-effectively, but most Dragons are faster than Kyureum. Earth Power doesn't have the benefit of STAB (or Sheer Force or a potential Download boost), but it is not walled by Heatran unlike Genesect. Perhaps Kyureum-B can take both of Talonflame attacks relatively well and KO back with Fusion Bolt, but it would get worn down by Rocks or scared out by a faster Pokemon or one with strong priority.
