24 May 2010 at 20:22 - 3
When you cast Arcane Echo you are 'enchanted', you are actually under the enchantment Arcane Echo. While under this enchantment, the next spell you cast replaces the slot on your skill bar that Arcane Echo is in. So you end up with 2 copies of a spell on your skill bar. So, if using SS like you describe, it would look like this:
[Arcane Echo][Spiteful Spirit]
{Spiteful Spirit][Spirit Spirit]
Each copy acts exactly as the original spell, but has a seperate recharge.