Full credit goes to: /u/Pamasich for working on it and helping me out with CSS, the below CSS I will mention is fully made by he/her with my feedback, again thank you!

To all kbin magazine moderators,

Below is the CSS you can use to include your own banner of choice to your Kbin magazine/community:

h1[hidden] {
    height: 12vh;
    background-image: url(https://i.imgur.com/wbZa4eI.png);
    background-size: cover;
    background-position: center;
    display: block;
    color: transparent;
    user-select: none;
}

DEMO: Check m/cars using this CSS

NOTE: Change height's value according to your needs to fit your banner accordingly. You should also replace the image link in the above CSS with your choice, I used imgur to upload the image there, and copy/paste the image's address/link here.

This is what we have so far thanks to /u/Pamasich, and I hope this comes to rescue all of the moderators just like myself.

Why should you add a banner? This simply makes the community look more appealing and welcoming for users to participate, depending on what kind of topic your magazine is based on, a banner is invaluable.

And if you guys have your own further modifications to the given CSS above, feel free to mention them in the comments so everyone else can find this thread useful in the future!