Stained Bandage in Anime Last Stand is a material that you need to evolve Hero Hunter into Hero Hunter (Bloodthirsty). Someone who has this One Punch Man character simply cannot avoid having an upgraded form. Since there are quests that need to be completed on Nightmare Difficulty, you would need to evolve Hero Hunter using a Stained Bandage in ALS. However, like any other item, you will have to complete some tasks before you can get it. To help you with that, here is a quick guide for you.

To get Stained Bandage in ALS, you need to complete Hero Association Act 6 in Story Mode. There is no way to craft this material, so getting it through Story Mode is the only way. However, you should know that playing Hero Association Act 6 on Normal difficulty will not guarantee you Stained Bandage. Instead, you should try playing it on Nightmare difficulty, as it has a 3% to 6% drop chance.

It is recommended to grind repeatedly in Hero Association Act 6 until you finally get a Stained Bandage in Anime Last Stand. Since you only need one of this material to evolve Hero Hunter into Hero Hunter (Bloodthirsty), you don’t need to repeat once you get the bandage. One more thing, to evolve Hero Hunter, you not only need a Stained Bandage, but also x25 Common Spirit Shard, x8 Rare Spirit Shard, x3 Epic Spirit Shard, and x3 Legendary Spirit Shard.

So far, Stained Bandages in Anime Last Stand have no other purpose than to evolve Hero Hunter, so you can breathe a sigh of relief if you've lost interest in this character.