Help Possible items/counters for Pajay?

[Lord Windos]

Thinking of writing a guide for Pajay. I've got its moveset, EVS and nature down, but am not sure of items that could benefit Pajay (other than, say, a Charti Berry to reduce its crippling weakness to Rock) or of some of its counters (e.g. is it able to take down Choice Scarf Nucleon fairly easy or does CS Nucleon tank a hit, then get faster, outspeed and one-shot Pajay?) Speaking of which, despite having read up on Smogon, I'm not fully sure as to the speed mechanic (Is a fully-invested base-100 speed Pokémon able to outspeed an uninvested base-110 speed Pokémon?)

Thoughts?

Heat Rock could be a great item for Pajay with Flash Fire (EDIT: When its added to the game), as it could switch into a Fire type like Inflagetah (well, maybe not them specially, but still), absorb a Flame Impact, and then set up Sun while shooting off what amounts to an 8X STAB on its Fire type moves, as STAB + Sunny Day + Flash Fire is a nasty combination nothing wants to take except Special Resistant walls. It even has Tailwind and a decent Speed/Sp. Atk tier to pull of a sweep if the condition are right, though Rock types like Theriamp and Astronite can still screw you over if they are packing their STABs. Fortunately Pajay gets Solar Beam/Steel Wing to deal with them if Necessary, though that means you are more easily walled by opposing Fire types if you don't go with a Flying STAB, and Roost could also be used over Tailwind if your are confidant they'll do fine without it and/or have a Baton Passer like Luxelong or Stenowatt to pass along Speed Boost/Sticky Web (When its working, that is). Decisions decisions!

Charcoal or Choice Specs is also nice too, if you want want your choice of limited firepower.

If a Nucleon is weaked by hazards or somehow tanked a hit, chances are a Strong attack will knock it over, especially if its physical, but the little green demon has such high S.Def and relativley good bulk that it may even survive a hit and retaliate, so make sure its either weakened or Pajay has a boost of some kind before directly engaging them (Has to have a CS and speed nature to outspeed the little devil, though). The same could be said for any other Pokemon fighting against it, of course, so this is more general advice than not, but still...

A Fully Invested Base 100 Speed Pokemon with a Speed Boosting Nature will outspeed an 110 Speed opponent that hasn't invested in it at all. Link to a calculate to do these sort of things yourself, if you are interested: https://pokemonshowdown.com/damagecalc/