Fire And Earth.

You could also look at it this way:
(Using your arrow example here.)
If you shoot arrows at fire, it won't do anything to the fire itself.
If you shoot arrows at a rock, the rock will slowly crumble.

and:

If you smashed someone as hard as possible with a big rock, it'll kill you on impact
If you smashed someone as hard as you can with fire of the same size as that rock, you'll only be dead once the fire has gone over the absolutely necessary parts of your body.


But to me it still seems more logical that it'd be the other way around. Just saying that from some points of view fire is defense and earth is offense.

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You could also look at it this way:
(Using your arrow example here.)
If you shoot arrows at fire, it won't do anything to the fire itself.
If you shoot arrows at a rock, the rock will slowly crumble.

and:

If you smashed someone as hard as possible with a big rock, it'll kill you on impact
If you smashed someone as hard as you can with fire of the same size as that rock, you'll only be dead once the fire has gone over the absolutely necessary parts of your body.


But to me it still seems more logical that it'd be the other way around. Just saying that from some points of view fire is defense and earth is offense.

 

I actually believe Undertale does it quite nicely.

The motherly, nurturing Toriel uses fire magic, but not chaotically to destroy. She mostly uses it for utilitarian purposes, such as cooking or defending you. If you examine a fireplace, it's specifically noted to be a very soft flame, one of warmth and nurturing, that you could stick your hand right inside with no issues. A nurturing, or guiding flame makes sense for a defensive aspect.