I find myself with a lot of items and I'm hesitant to discard something that requires 1000, 2000, etc kills if I don't know what the boost is. Is there a way to figure out what it is, simply based on how many kills it requires?
The KO requirement does determine what kind of skill would be on the weapon. But there is no official way to. There was a bug that may or may not have been fixed that does allowed you to figure out the exact skill if the weapon also has an empty slot.
- The weapon with the KO Skill on it needs an extra slot.
- Try forging a possible option into that slot. It will not let you add it if the KO Skill is that one (because you can't have two of the same skill on a weapon.)
- e.g. If a weapon has an empty slot and a KO Skill that needs 2000 kills try putting any of the VS Skills you have onto the weapon. If it DOES NOT let you put that skill on the weapon that is the skill that will be unlocked.
The actual possible skills can be found here: http://koei.wikia.com/wiki/Hyrule_Warriors/Weapon_Skills
1000 KO Skill: Health+, Special+, Bombs+, Arrows+, Boomerang+, Hookshot+
2000 KO Skills: VS Legend, VS Skyward, VS Twilight, VS Time, VS Sorceress, VS Ganon, VS Soldier, VS Undead, VS Beast, VS Dragon
3000 KO Skills: Compatriot, One-Hit Kill, Sturdy Feet, Regen, Defenseless, No Healing, Adversity
(After 1.5 Update) 4000 KO Skills: Hasty Attacks, Normal Attacks+, Special Attack+, Finishing Blow+, Focus Spirit+, Heartstrong
25,000 KO Skills (Kills only start to count on these weapons after getting every original Weapons in the game) Evil's Bane ( Str+200), Legendary (Str+300)
There are sets of slot skills (the upgrades for weapons). X1000 are all upgrades for tools (bow,boomerang,ect) with enough kills. X2000 are all extra damage on specific characters and units in a category (like twilight characters). X3000 are mostly (not all) extra damage with requirements (for example, you can't heal, you have low health, ect.) One exception I know is more damage taken, but less knockback.