Mage Slayer in Dota 2: Why is it so strong?

It seems like every Dota 2 player is building Mage Slayer. In pubs, ranked, and pro matches alike, this item is seemingly in every game on any hero. But why? Just a couple patches ago the Mage Slayer was just a random component for Bloodthorn. Why now and what has changed for the item to become the star of 7.34b? Well let's break it down.

Created back in 7.28, Mage Slayer was a forgotten item at the time. It was seen as quite the niche item to counter spellcasting heavy heroes like Bristleback, Leshrac or Timbersaw. The item required a Cloak, Blade of Alacrity, Claymore and a 600 gold recipe. This combination led to an item that provided 20% Magic Resistance, 20 Agility, 20 damage and Attack placed a -35% Spell Amp debuff on enemy heroes for four seconds. Originally, the item built into Bloodthorn rather, which was the only time the item saw usage.

At the time, the item wasn't worth the bonuses that it provided. So it became a somewhat forgotten, only as a component of a larger item. However this wouldn't be the case for long. In both 7.35 and 7.35b Mage Slayer got back to back buffs. The first patch saw the item being developed into a standalone item rather than a component of Bloodthorn. Which meant that the item got a couple much needed buffs.

The major change was that the item now provided a 20 damage over time effect on top of the debuff. This new DoT effect worked wonders with the item, as Mage Slayer instead of providing additional damage gave +45 attack speed to heroes. Then in 7.35b, the Spell Damage debuff was increased to 40% rather than 35%. The combination of all these changes skyrocketed the item into one of the most build items of the patch for heroes.

Here are Mage Slayer current stats:

Despite the changes, the question still needs to be asked and answered. How come this random item is so strong? Well it all comes down to the debuff that Mage Slayer applies to enemy heroes. There are few if any heroes in Dota 2 that can have a major impact in team fights while the debuff is active. While enemies are affected by the debuff, your allies essentially have 40% more effective HP which is a lot of health at the end of the day. Coupled with the fact that the bonuses provided work for any core lane, and you can see why Mage Slayer's popularity is where it's at.

For example, let's take the most popular Dota 2 hero: Pudge. Typically Pudge deals his damage through his Rot ability. While in the AOE rot does base 120 damage to enemy heroes. However, if affected by Mage Slayer and the enemy hero has the item equipped, that hero is taking 65% less damage. The 25% magic resistance from the item itself on top of the 40% spell damage debuff. While on Pudge takes his own damage from the ability, he's also taking 20 damage per second while affected by the the item's debuff.

It's truly not a surprise that Mage Slayer is this strong, the item is everywhere. There are two sides to the coin, you either love the fact that Mage Slayer has finally gained popularity or hate that the item is everywhere. Either way for now, and for the upcoming Dota tournaments, Mage Slayer is here to stay. For more Dota 2 content, stay tuned to esports.gg