Charging your Special Power Meter
First of all, let's have a look at how the special meter actually recharges. Every time you attack, the special meter increases by a certain percentage. The actual percentage is the product of your current recharge base, your Willpower factor, and the current item factor. The recharge base is 0,2 and is multiplied by your current movement cost. This is done to ensure that your special doesn't regenerate faster with lower movement cost. The Willpower factor is your Willpower divided by 16, and the item factor is the sum of your equipment's special regeneration bonus. So at Willpower 16, with no item bonuses, you will recharge your special every 500 time units (as long as you are always attacking). This is already fast enough to have two special powers activated simultaneously (Eagle Eye and Power Strike last for 750 time units, e.g.), as long as you are attacking most of the time.
Well, that's it. Not more to say about how the special regeneration works. Let's get to the cool stuff:
I won't do the math for you, but it's certainly not the +1 to Willpower that make this armor a must have for your special-relying build. Plus it gives you a great bonus on magic resistance, which makes it one of the most desirable armors even for high level characters.
Where is my Laden Chains?
Rumors say the Skeleton King has some in his treasures. Jintresses are a good bet, too. Why don't you just clear up the Desert Temple, Oasis, and Sacred Pyramid altogether a few times? Oh yes, and don't forget the second challenge!