Not only do you have to use it, but you have to use it as your last action. Unfortunately, that means that if you play in solo mode, on top of the trouble of having only one character, you'd be unable to raise natural defense until late in the game.
My NES, SNES, and GB all work just fine. Why should I downgrade to a Wii U, PS4, or XBone?
F***. Should I stick with agility weapons, since agility affects more than strength?
Depends on how you want to play. Agility is generally accepted as the strongest stat, since it affects so much and there are some great agility-based items in the game. But, if you don't mind additional time to grind for strength (or if you want to make a STR robot), then you will find there are some great strength-based weapons, as well - especially for the endgame (XCalibr and Gungnir).
Some endgame weapons to consider:
Gungnir: STR-based, high group damage XCalibr: STR-based, high group damage, infinite uses (even for humans/mutants) Muramas: STR-based, high single target damage Sun sword: STR-based, high single target damage Defend sword: STR-based, high single target damage + blocks direct melee attacks if used Seven sword: STR-based, highest damage in the game --- CatClaw: AGI-based, high single target damage Samurai bow: AGI-based (for Robots), high group damage
Strength-based weapons can offer the highest damage in the game, and you have a lot of different options to pick from. The downside being that you have to have an agility stat worth something, too, to make it worth it. Otherwise, AGI robots are quick and easy to make and are really, really strong throughout the entire game.
The nice thing is that you can use whips to level up your AGI while still having a competent attack. Their damage is based on STR, but they raise AGI. There used to be a good rule of thumb to follow for minimum AGI, but I don't remember now (was it something like 30 by Venus' World?).
That's not entirely correct. You don't have to use the item but the character must have their turn. If you kill the enemy they're targeting but there's more enemies it'll say the character does nothing (which gives him/her a chance to gain a stat) but if all enemies are killed prior to him/her every getting a chance to act they won't be able to gain a stat.
from what i've read from the let's play threads, best character to deal with endgame bosses is a human. train the human up in agility weapons first, then later magic(humans can increase mana faster than mutants), and finally rely on endgame armor to boost his strength to make full use the endgame swords.
that means a lot more grinding though, if you want to create the perfect boss killing/tanking human.