Well, none of my magic is op. So technically, yes you can, and your physical strength and size will be increased tenfold, but any damage you take while in bear form will take its toll on your real form when reverted back to. Also, like most forms or beings, after taking much damage you will be reverted back to human form. Although, since it is a giant armoured bear, I'm guessing that it can take a few hits. Or maybe like, a lot. You also won't be able to use your spear while in this form, so don't rely on it too much.