Dark Seer

Dark Seer is a support caster hero that employs his skills to fully disorient his enemies through vacuums and illusions, as well as support his allies. As a melee hero, his overall attack and natural movement speed doesn't improve over time, making any follow-up melee attacks very risky. He's also a very versatile hero; He can gank with Vacuum, push with Ion Shell, initiate with Wall of Replica, support with Surge, giving him a persistent role on a team. To be played effectively, he requires skill, prescience, and most offputtingly for new players: boldness and daring. He is recommended for intermediate to advanced players.

Tips

 * With a Stout Shield and healing items, Dark Seer can start jungling almost immediately.
 * An advanced jungling tactic involves Smoke of Deceit. By combining it with Ion Shell, Dark Seer can jungle without taking any damage from creeps, as the only thing that removes the invisibility is proximity to an enemy hero or auto attacking a unit. In this way, Dark Seer can stack a single camp multiple times, cast Ion Shell on himself, pop Smoke, and stand at the camp until the creeps have been killed. Because of the steep cost of Smoke, it is advised that players do not use it without stacking camps first. Since the July 26th patch neutrals will now run away when attacked by an invisible enemy, unabling this method of jungling.
 * 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 will chase enemy heroes.
 * Be sure to take at least 1 early point of Surge, as it can help escaping ganks and chasing, as well as giving more mobility.
 * When chasing, self-cast Ion Shell and run next to the enemy without attacking, using Surge if you need to catch up. Even better, use surge to body-block enemy heroes (that is, get in front of them to hinder their movement) and deliver auto-attacks without moving out of range of the Ion Shell.
 * Wall of Replica is usually skilled after you've maxed both Ion Shell and Vacuum, as early game illusions don't deal much damage. Additionally, the relatively high mana cost at lower levels can be prohibitive, as you won't be left with much mana to cast other spells.
 * AoE spells, especially those that require positioning, greatly benefit from Vacuum, as you can place all of them together to ensure a hit.
 * Using Vacuum on enemy heroes to send them through your Wall of Replica will disallow foes from preventing illusions, as well as causing guaranteed damage from passing through the Wall.
 * Due to Vacuum and Ion Shell's instant cast, your usefulness in large team fights permit Dark Seer to synergize extremely well with heroes such as Enigma and Jakiro. Make sure to cast these abilities with Black Hole and Ice Path/Macropyre/Liquid Fire to maximize AoE damage and maybe turn the tide in battle.