One of my characters rely on their mind more then physical , however, they are required to use a weapon for battling. What is an easy weapon they could use if they don’t have much fighting experience?
Unless you literally mean they have psychic powers, that is how people fight. It doesn’t matter how strong, fast, or tough someone is, if you can outwit them, they’re fucked. This is why, the ability to think, and adapt is the primary attribute for a fighter.
I realize people like to say, “my character is different, they think about how they fight,” but it’s really a lot like saying, “my character is different, they use the turn signals while driving.” Yeah, you don’t need to, but it’s not going to end well.
Stepping back from that a moment, a smart fighter learns a wide variety of weapons, and picks the ones that will be most useful for the opponents, terrain, and situations they’ll be facing. That means learning as many weapons as they can.
There’s a strong bias in media for characters who hyper-specialize on a single weapon. The master swordsman, master martial artist, the gunslinger, the sniper, the archer. You know how to stop someone like that? Pick a weapon or strategy they can’t defend against. It doesn’t matter how good you are with a sword if someone else guns you down.
Being adaptable and merely proficient with a variety of options is often far more dangerous than someone who was studying the blade while you were reading this.