Online: Perfect Wild Impulse
Perfect Wild Impulse is a Blackrose Weapons item set awarded from Blackrose Prison at Veteran difficulty. If you do so at Normal difficulty, you will instead receive the Wild Impulse set, which lacks Spell Penetration.
Set pieces are Honor Guard Style.
2 items: Adds 17-1190 Spell Penetration
2 items: Reduce the cost of Impulse by 10%. Impulse places lingering elemental damage on your targets, dealing 92-3965 Flame, 92-3965 Shock, and 92-3965 Frost Damage over 8 seconds.
While the description states that 2 items are required, this is because staves are 2-handed weapons, and thus count as 2 items by themselves, so only 1 item is actually needed.