I just need to pre-face this by saying I'm not trying to sound rude, I'm just saying stuff...
JES, if you're half serious about SRing legendary Pokemon, one would assume you have a basic understanding of Pokemon and the availability of certain moves / items, and if you didn't then you would at least do some research first, such as 'where can I get an Air Balloon?' and 'how does Sableye learn Pain Split?' before starting to breed. It is certainly not Buckerts fault that you failed to do so. You also should have also noticed in the OP that Buckert is (very generously) giving away free clones of the Pokemon that you need which would have saved you the trouble of breeding for that Smeargle (which still isn't a waste because you'll get that much mileage out if it that it's worth it). Unfortunately, the Sableye that you need isn't yet available in Buckerts giveaway but that is understandable due to the sheer amount of work that he is already putting into the guide / the other Pokemon needed. If you need it so desperately you can still breed / train your own Sableye and ask in the Wi-Fi forums Simple Request thread to have it tutored Pain Split and have an Air Balloon attached. There are many users who will probably help you out for free, or you may be asked to trade them something nice for their troubles like a good breeding spitback or something... OR you can just forgo the HP check and just do a speed check with a Staraptor with Intimidate (like I did). If you want to do a HP check and are restricted to stuff in ORAS (which I know you're not because you're breeding a Smeargle which isn't obtainable in that game but whatever) then I would recommend this:
Dusclops (Lv.62) @ Eviolite
Ability: Frisk (Pressure will cut Rayquazas PP down)
[any +SpDef nature]
EVs: 252 Def / 252 SpDef
- Night Shade
- Memento
-
-
Two uses of Night Shade will be 124 damage, which is exactly 50% of Rayquazas HP if it has a 30-31 IV, if after two Night Shades his health is yellow reset, if it's green then you've confirmed the IV is 30-31. With max Def+SpD, Dusclops can survive a +1 critical hit Fly as well as back-to-back crit Dragon Pulses, allowing you to get the two Night Shades in. Then you can Memento out to give Smeargle a safe switch in. This means your team would be: [fainted sync] / [speed checker] / Dusclops / Smeargle / [empty] / [Rayquazas spot]
That should help you out. Next time, do some research yourself instead of coming here to complain that the guide has mislead you... Buckert shouldn't have to put a disclaimer in every entry saying how to get stuff, some common sense is needed
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Also
Buckert, can I suggest changing Swords Dance on the Rayquaza Smeargle to Night Shade / Seismic Toss? Swords Dance + False Swipe is a 6-7 turn set up whereas two uses of NS/ST will do 200 damage, which leaves 48 HP, +0 Silk Scarf False Swipe does at least 27HP damage so two of those will bring it to 1HP, which is a 4 turn set up (that was with a 31 attack IV, if Smeargles attack is that low then maybe you could swap Recover for Dragon Rage to do the set 40HP, then False Swipe it to 1...)
edit: Sturdy Endeavor Aron also works to bring him down to low health quickly
edit 2: if you're not using Smeargle to check stats then Spore + False Swipe Breloom hits Ray much harder