Item tier 1: Empty Stone
Specification: 6% chance on attack to discard 40% of current hp points, for multi-target towers 3% chance
Item tier 2: Blank Stone
Specification: 13% chance on attack to discard 60% of current hp points, for multi-target towers 5% chance
Item tier 3: Void Stone
Specification: 6% chance on attack to discard 40% of max hp points, for multi-target towers 3% chance
Item tier 4: Black Hole
Specification: 3% chance on attack to vanish units in 600 radius, for multi-target towers 1% chance
Item tier 1: Wand of Wizard
Specification: Every attack recovers mana by 3%, 20% chance to deal 40% of max mana to enemy
Item tier 2: Wand of Magus
Specification: Every attack recovers mana by 3%, 25% chance to deal 60% of max mana to enemy
Item tier 3: Wand of Sage
Specification: Every attack recovers mana by 5%, 20% chance to deal max mana to enemy.
Item tier 3: Wand of Sacred Wisdom
Specification: Bonus mana +100%, every attack recovers mana by 1%, +2 attack target number (barrage). When mana reaches 100% gives all your other towers +50% attack speed, and this tower reduce attack speed by 50%. Mana resets to zero. Cooldown 2 minutes.