So this just gets stuck with me and that's why I write this
As you can see in the title The protagonist is a Bard the one where it tells story with music. So basically the premise of this is the MC gets stronger through people believing his story and Gets a high emotion on his music.
Example he sings a music about love and couples who hears it remembered their past on how they became a couple, or just a story about a certain strong person who killed a demon with a magical sword.
About his powers it relates to music and story, like music can charm people or even make them succumb to you and be your loyal fanatics, Music notes that can be used to attack like in doctor strange. Story that can summon what was believed by people according to your current power.
that's basically it.