Pokémon Legends: Arceus has many strange, seemingly pointless items, and many could be led to believe the Electrizer is one of them. But, in actuality, this item is the only key to evolving a Electabuzz into the massive Electivire. Good news is, if you already have caught Electabuzz, it should be relatively easy to obtain the Electrizer.
Within Jubilife Village, trainers can buy the item from the Trading Post which is right outside of the Training Ground. It will be up for sale for 1,400 Merit Points, a currency that can only be obtained through picking up satchels that are throughout the wild. If you already have an Electabuzz, you likely have enough locations unlocked for there to be a good amount of satchels lying around. Each will grant you up to 100 Merit Points; so, this process should be fairly short.
If you desire to get the Electrizer at no cost, you will have to travel through a Space-Time Distortion and defeat Pokémon, in the hopes that they drop it as loot. The chances of this happening is relatively low, but some may find this easier and more beneficial than finding satchels. Once you’ve received the item, you’ll be allowed to evolve Electabuzz, with no other requirements needed.