>>42920003You just have to get the Stamp upgrade in the shop, then stamps will drop for your weapon in runs. The solo stamp is also known as the Akukin stamp, I didn't actually pay attention to the name. It gives you 20/30/40% damage on your weapon for every empty weapon slot you have (which you can force in the shop!) and I've breezed through every stage with it. It's also very fun to me. Getting to swish-swish with Katanas is cool! Nobody can tell me otherwise!
