Arrow of Thunder

At lv 1 you get

• Attacks you make with ranged weapons are considered magical for the purposes of overcoming resistance and immunity to nonmagical attacks.
• When you make an attack roll with a ranged weapon, if you would load no ammunition, you magically create a piece of ammunition as you make the attack. This ammunition disappears one minute after you make the attack whether you hit or miss.
• When you hit with an attack roll with a ranged weapon it deals an additional 1d4 thunder damage

At lv 3 you get

• increase 1d4 thunder damage to 1d6 thunder damage
• you get 5 thunder points, and recharge all thunder points on a long rest
• on a hit you can use a thunder point to use, Thunder Surge, or Thunder Fizzle
• Thunder Surge- Thunder Surges in the flying arrow and into the enemy dealing 1d8 extra damage
• Thunder Fizzle- Thunder fly's out of the enemy dealing 1d4 thunder damage to up to 3 enemies in a 10 ft radius around the enemy attacked besides the original enemy

At lv 5 you get

• you get additional 5 thunder points, for a total of 10
  
• change thunder surge to thunder strike, and Thunder Fizzle to Thunder Cain
• Thunder Strike, thunder strikes your targeted enemy dealing 2d8 thunder damage extra damage 
• Thunder Chain, thunder chains to up to 5 nearby enemies dealing 1d6 thunder damage around the enemy attacked besides the original enemy

At lv 10 you get

• increase 1d6 thunder damage to 1d8 thunder damage
• change Thunder Strike to Thunder Overcharge and Thunder Chain to Thunder burst
• Thunder Overcharge, overcharge you enemy with 3d8 thunder damage extra damage 
• Thunder Burst, attack all enemies with 2d6 thunder damage in a 15 ft radius around the enemy attacked besides the original enemy

Notes: First magic item I've made please give constructive criticism not just that I'm bad at making items, a necklace that has a thunder symbol and an arrow in a X shape at the bottom