Not every member of the Elite Four has the strongest Pokemon in the world.
That is evident by how easy some of the Elite Four battles have been across the many Generations of Pokemon games. There always seems to be at least one Elite four trainer who is a pushover.
Naturally, that must mean their Pokemon are weaker than that of the other Elite Four members. Of course, their Pokemon could probably beat a variety of trainers. That is why they are in the Elite Four. But when it comes to facing off against well-prepared battlers, weak is all they can be called.
Note: This article is subjective and reflects the opinion of the writer.
5 weakest Elite 4 Pokemon
#5 - Aaron's Dustox
Bug-types are notorious for being named the weakest type in Pokemon. Therefore, having a Bug-type themed Elite Four member is a bit of a head scratcher. Some of Aaron's Pokemon can be a pain in battle. His first, however, is Dustox. It is pretty weak compared to the rest. Of course, any Fire-type will take them all out, but Dustox doesn't really do anything except try and poison with Toxic.
#4 - Flint's Rapidash
A Fire-type Elite Four member is going to be devastated by Water-type Pokemon. Even Flint's Steelix has that weakness. Only his Drifblim can withstand the onslaught. His first Pokemon sent out, Rapidash, is quick and agile. That is its biggest strength. It also knows Bounce and Solar Beam. If it can charge it and withstand some hits, a Water-type could be done for. Otherwise, it is easily defeated.
#3 - Bruno's Onix
The first Onix that Bruno throws into battle is incredibly weak. This Kanto Elite Four member can put up a fight with the rest of his Pokemon, but Onix can be taken out in one hit. If the player chose either the Water or Grass starter, it is done for. Even with a Fighting-type Pokemon, Onix is beat. A Rock/Ground-type just has too many weaknesses for it to stand a chance.
#2 - Kahili's Skarmory
Kahili is the Flying-type expert of the Alolan Elite Four. Her Skarmory can be bested quite easily. Skarmory is a wonderful Pokemon that can take on a variety of roles on any team. It is weak to Fire and Electric moves and doesn't do much to withstand that. Slash, Feint, and Steel Wing are its attacking moves. Talk about lackluster. It can set up Spikes, however, so watch out for that.
#1 - Siebold's Clawitzer
Siebold is an Elite Four member in the weakest region. The Kalos Elite Four are pretty awful and a Water-type user is just laughable. A lot of Kalos players went with Froakie and will have a Greninja at this point. Even the same type match up proves to be in the trainer's favor. A Grass or Electric Pokemon, however, would wipe out Clawitzer in a single hit.