Soldiers and warriors are very present in the manga, they are particularly represented in the Shōnen and Seinen.
So, here my tutorial of a strong and muscular soldier, in Manga / Anime style.
Start by drawing the approximate shape of your character.
Do not press too hard on your pencil because these traits will be erased afterwards.
Using the first step, draw the outline of your character.
By helping you of the previous step, draw the details of your character.
Draw the different lines of the character with felt pen with a skinny point and take off the marks of gray pencil with a rubber.
Now with a software like Adobe Photoshop, felt pen or colored pencil, color the character with the main colors.
Now you just have to add details on the soldier’s pants and on his sword as well as light and shadow effects to make your character more realistic.