Dark Seer/Guide

General

 * If laning, be sure to harass enemies with Ion Shell by placing it on their melee creeps (for melee heroes) or ranged creeps (for ranged heroes). Additionally, placing Ion Shell on the second allied melee creep to arrive at the creep line is a good way to push the lane as well as create a moving damage-dealing creep that chases enemy heroes. This can make it hard for the enemy carry to last hit, as they have to do it under the tower and while taking damage from creep aggro and ion shell at the same time.
 * Dark Seer can farm rapidly in lane and jungle thanks to Ion Shell. To jungle, stack the hard and medium camps several times, and then place an ion shell on one of the lesser creeps. The shell should clear out the whole camp(including the stacks). Do this repeatedly to accumulate a large sum of gold. However, be sure to stay within experience range.


 * Due to Vacuum being able to clump up a large group of enemies fast, and Ion Shell's high damage output considering enemies are affected by it for a longer while, they permit Dark Seer to synergize extremely well with heroes such as and . Make sure to cast these abilities with  and // to maximize AoE damage and maybe turn the tide in battle.
 * AoE spells, especially those that require positioning, greatly benefit from Vacuum, as it can place all of them together to ensure a hit.


 * When chasing, self-cast Ion Shell and run next to the enemy without attacking, using Surge if the enemy is faster. Even better, use surge to body-block enemy heroes (that is, get in front of them to hinder their movement) and deal damage with basic attacks without moving out of range of the Ion Shell.


 * Surge can be cast on the team's, allowing it to get out of danger, or finish its delivery to allies faster.
 * While normally pushing the lane is a bad thing, and his high Strength gain makes it hard for the enemies to lock down Dark Seer and kill him.


 * Using Vacuum on enemy heroes to send them through Wall of Replica disallows foes from preventing illusions, as well as causing guaranteed damage from passing through the Wall.

Items
Starting Items:
 * gives you resistance to physical attacks whether you are laning or jungling.
 * es cover your health and mana issues until you build up your early game items.
 * es is beneficial with its early boost to Dark Seer's attributes, but also help you build up to a and/or  later on.
 * can be considered as it can be assembled in the side shop and lets your team use the courier more. This is especially important if your midlaner plans on getting a quickly.

Early Game:
 * covers most of your mana issues and allows you to constantly cast your Ion Shell in order to harass your lane opponents and get some last hits.
 * gives mobility for chasing or running away.

Core Items:
 * allows you to sustain your presence in fights.
 * increase your mana pool and allow you to give your teammates mana.
 * adds to Dark Seer's teamfight effectiveness and increases your durability. Also his decent Intelligence gain means he will generally have enough mana to use the heal.
 * allows you to be at any lane for a gank, countergank, or push in seconds.

Situational Items:
 * can also be used to sustain high mana use, if the Dark Seer is put midlane. It has the added benefit of rune control as most runes are useful for Ion Shell harass.
 * can protect your team from enemy carries in teamfights.
 * effectively allows your illusions to deal more damage than your opponents, thereby significantly increasing your team fight potential.
 * grants you magic resist and a lot of health regeneration, and can be upgraded into a Pipe of Insight.
 * grants you and your allies protection from magic damage.
 * can help you positioning to place a better Wall into Vacuum combo.
 * should be considered to counter high physical damage dealers and it is relatively cheap.
 * is always a great pickup for the hex and mana regen. If you need to turn off a carry's damage output, this is a very strong pickup.
 * grants you more punch to your and  initiation, and gives you armor and intelligence.
 * allows you to initiate with little fear of dying.
 * allows you to cast your abilities and items twice in a row if needed.