A redraw of the Sprite would work? I mean, I believe that may work.
He means draw the sprite so it looks like original, just make it larger. Or you can use resize, but that results in loss of quality.
There are also plugins that allow to use custom weapon graphics. I think one is even made by Yanfly.
If you draw out the sprite but larger and add it as if it was a custom weapon using Yanfly's Weapon Animation plugin it should work quite well. The animation is just three frames, so I assume drawing the larger sprite it would work Ideal.
Well at least for what I know if you use actor battlers as enemy's then you can attach weapons and they can also be custom weapons. However this is also one of Yanfly's Plugins.
Its called Animated Side view enemies: http://yanfly.moe/2015/12/13/yep-44-animated-sideview-enemies/
However It would require a second one if you want to add a custom weapon instead of one of the default ones.
http://yanfly.moe/2016/01/28/yep-63-weapon-animation/
I believe in the parameters of the plugin you would have to identify the 'Attack motion' and the 'Weapon Image Index'
In the parameters of the plugin directly if I am not mistaken.
Not on all the enemies, fortunately the weapons would have to be added to the plugin's parameters. I took a shot of what I am seeing within the parameters. https://gyazo.com/c2359c08be205a4057f8d2fa8a14add4 The weapons that come with the RPGMaker should already be ready to use since thier is a weapon sheet in the files which are listed in order in the Help section of the plugin. If you were to use a weapon of this spread sheet then you can put this command in the Notes of an enemy along with the other necessary notes.
<Sideview Weapon: 1>
However the number can be any number within those that are listed in the shot I took above, but I have not tried to add custom weapons to a Sideview enemy so I cant speak of that being sure. I do see a few custom slots in their so I assume their is a way to add much more.