Magnemite: A to A-
Magnemite still is a powerful and dangerous scarfer, but I think the meta's adapted well to mag's rise in usage and it isn't as good as it was a month or two ago.
With protect becoming mandatory on gull and being a popular 4th move option for onix, scarfmag can't freely volt or force 50/50 like scenarios anymore. Now, you're forced to double to avoid being trapped or losing momentum.
Opposing mag pull scarfmag similarly makes your own mag a liability, especially when paired with protect mons or dig/trap since you're almost forced never to click flash or tbolt if you need the mag, otherwise opposing mag traps and removes.
The increasing trapinch usage also doesn't help mag at all, since it stops mindless spamming of volt but, unlike dig, trap can easily stomach two flash cannons if carrying bj and even evio trapinch can tank two timid flash cannons.
Mag is still good. It can decimate some teams not carrying an elec immunity with ease and trapping ferros, opposing mags locked into anything other than a hp and scarf pawn locked into iron head is still solid but with the metagame adapting to better deal with mag, I don't think it does what it wants to do consistently enough to warrant being ranked in A. Sturdyjuice mag is probably better than it was earlier since it can take advantage of opponents maybe assuming it's scarf and is a good check to a decent number of mons but the ever present knock is annoying. The loss in effectiveness of mag's most common set makes it not worthy of A anymore imo.
Agree with:
Spritzee to A
Mareanie to A
Chespin to C+
Trapinch to B+
Foongus to S
Disagree with the gastly drop. I'd argue that gastly is closer to A+ than A- since it's so versatile in what it can run and do. It hits ridiculously hard with lo and trying to switch into it or play around it is not easy.
Gast is really versatile, being able to viably run probably 4 different z move sets depending on what the rest of the team needs lured and removed. The life orb set only has sludge bomb as a real necessity on every team, meaning it has 3 free moveslots to run whatever combination of coverage/support moves it wants to support the rest of the team and remove certain mons. Being able to run sludge + any three from psychic, shadow ball, dazz, tbolt, sub, hp fight, hp fire, sucker, wisp is really good if you pick the correct coverage to support the team best. Heavily pressures the standard regen mons and defensive mons like sprit and is a powerful breaker vs most teams, especially teams without any form of pursuit trapper.
On top of z move and lo, it can also run its willohex set and act as a scarf cleaner.
The fact that nearly all gast sets only have one viable safe switchin in grimer-A and two less viable switchins in munch and stunky makes it really difficult to play against if you're not packing those mons.
Defensively, gast is very frail and usually you have to get it in with voltturn or free switches since doubles can be risky. However, I don't think knock off from slower mons like timburr or mienfoo or vull are hugely threatening to gast. Gast can't switch into them but these mons also can't safely switch into gast and, depending on sets, can't force gast out either even on free switchins. Tim and fastfoo die to lo psychic from full, all bj vull die to lo tbolt barring the 26 hp 15 spdef set, which has a 6/16 chance to live. All offensive bj sets die to sludge after rocks, and bulkier sets only switch in and force gast out once. Evio pawn has to win 50/50s if the gast is sub hp fight. It's true that gast can't pack all these coverage moves, but similarly scouting for coverage without losing mons is also tough. Sometimes, you just have to let it get a kill and trap or hope it's not running certain coverage moves.
Pursuit scarfpawn and pursuit dig are definitely annoying for gastly but can, to some extent, be mitigated by sub or by teammates. At worst in these matchups, you typically get a kill then get trapped but, if you predict well or remove them with other team members, gast becomes very dangerous.
The immunities to normal, fight and ground are also surprisingly useful, making opps think twice about clicking hjk with foo or stop them being able to spam return/earthquake freely with scarfbray/scarfbunny. Getting an unexpected kill or knock or chip due to an opp overpredicting is also nice. Immunity to fake out, feint, mach punch and vac wave is also great. Gast's typing does allow it to semi-comfortably stomach a foongus sludge/giga and spritzee moonblast and put a lot of pressure on the opp in return, so it's not defensively completely useless.
It was used 62 times during lcpl, putting it in top 15 or top 10 most used mons in sm in lcpl. Overall, I think it's definitely deserving of its A ranking just for its offensive capabilities.