Luden's Tempest

3400
High burst damage, good against fragile foes

80 Ability Power
6 Magic Penetration
600 Mana
20 Ability Haste
Echo: Damaging Abilities deal an additional (100 + 10% Ability Power) magic damage to the target and 3 nearby enemies and grants you 15% Move Speed for 2 seconds (10s cooldown). Dealing ability damage to Champions reduces this item's cooldown by 0.5 second, up to 3 seconds per spell cast.

Mythic Passive: Grants all other Legendary items 5 Magic Penetration.
Builds From

Lost Chapter Restores Mana upon levelling up. 80 Blasting Wand Moderately increases Ability Power 850
Builds Into

Eye of Luden 0