Invoker

Quas Exort: Sunstrike opponents fountain to check opponents items and infer lanes.

Quas Exort: Look around the map as much as you can for potential Sunstrike kills.

Quas Exort: You can use Sunstrike here and there to secure ranged creep last hit.

Quas Wex: Use Tornado and EMP to secure a last hit or deny a creep, and burn opponents mana at the same time.

Quas Exort: Use Forged Spirits to control runes.

If you play Quas Wex, then control active runes and look for opportunities to rotate once you have Treads and Spirit Vessel.

If you play Quas Exort, then avoid rotating and running around. Farm, pressure opponents' tower and look for Sun Strikes.

After ganking few times with Spirit Vessel, consider going back for Hand of Midas if the game slows down.

When not much is happening, you can easily split push with summons or by dumping spells from fog.

Don't forget to use Alacrity on yourself or right-clicking ally in the fights. Works well with Cold Snap.

Use Forged Spirits or Sunstrike to scout if opponents are missing.

Invoker is great at enabling team to take Roshan early due to Alacrity, Forged Spirits and Cold Snap.

Aghanims Scepter is a huge powerspike if you have a setup within the team, such as Chronosphere.

Identify which Invoker type you are playing against, by looking at invoked spells and orbs above Invoker. Quas Exort Invoker is farm and burst oriented and uses the Sunstrike ability early on. While Quas Wex is ganking and control oriented and uses Tornado + EMP and Cold Snap + Urn of Shadows combinations.

Invoker is squishy and the only real defense he has are his spells. Try to gank him early in the game with Smoke of Deceit and Dust of Appearance.

Opt for anti-magic damage items against Invoker

Dodging or surviving Invoker's opening combination of spells, makes him weak for 5 to 10 seconds depending on the cooldown of his Invoke ability.

Keep in mind that Invokers Tornado dispels. Active rune buffs and many spells are countered by it.

Aghanim's Scepter grants Invoker Cataclysm spell. Be aware of it and be mindful about your hero's position during it.