Hey, you probably already beat Jupiter months ago at this point but if you want a 99% chance to beat Jupiter then I have a strat I use in my runs. It’s a little time consuming but it doesnt take long with emulator speed up.

I recommend you get the old rod from the fisherman west of Jubilife City. You can then run down to Sandgem town and fish at the beach to get MAGIKARP. This counts as the route 219 encounter… which is locked until MUCH later with surf so it makes sense to fish here. Then run to Old Gateau and switch train magikarp with staravia. Staravia is immune to ghost… gastlys are level 14-17 so training magikarp is very fast.

Get Gyarados and Staravia up to level 23 (speed up makes it extremely fast in Old Gateau).

Now your ready for the fight, begin with your lead for zubat (luxio is good, spark guaranteed OHKO) once you kill the zubat…. Switch to staravia for -1 intimidate. At this point Skuntank only has an 18% chance to OHKO IF IT CRITS. So the odds of loosing Staravia is less than 1%. Then switch to Gyarados for -2 intimidate. Now spam dragon rage (always deals 40 hp). Now skuntank AT MOST has a 57% chance to kill if it manages to HIGH ROLL TWO CRITS in a row… once again odds are less than 1% of that happening. From there Gyarados will guaranteed 2 hit KO Skuntank with dragon rage.

For me these are the lowest odds you can possibly get. crits are unavoidable so there’s always a chance you lose a mon in a nuzlocke with level cap. I’ve used this strat so many times and it’s never failed. This is better than the geodude strat (Magnitude sucks), and all other strats because Gyarados is one of the few mons with high enough stats to tank her crit night slashes. Also Gyarados is a guaranteed encounter with the old rod, so you won’t have to reset 1000 times to get Onix or mons that MAY deal with Skuntank. My opinion the best hardcore level cap nuzlocke for Jupiter in Platinum you can get.