Helpful Tips for Invoker's spells

Tornado

Forge Spirit

Cold Snap

Ice Wall

Chaos Meteor

Alacrity

Ghost Walk

Deafening Blast

Sun Strike

EMP

Tornado can be used to stack creep camps by lifting them in at the spawn time.  Damage is dealt immediately after landing; it prevents the use of Blink Dagger.  Tornado is a good spell to have ready against Pudge.  If hooked, Tornado nearby anywhere asap and you might avoid Dismember. You can use it for Sun Strikes or hunt heroes in the trees.  Tornado removes the following buffs:If timed properly, Tornado will ignore Spiked Carapace as long as carapace expires before lift duration.  Remember that enemies are completely invulnerable while cycloned, so you still need to time your spells to hit after they land.  The cyclone duration is based on Quas, so be mindful of how many levels of Quas you have as well.  Tornado provides flying vision along its path as it travels, so it can be used as a scouting spell of sorts if you need to find an enemy in the fog of war.  You and your team can subsequently use this vision in combination with your other spells, such as following up a successful cyclone with a global range Sun Strike. You can block hooks/arrow by summoning spirit!  Use smoke on Forge Spirits and have entire team backdoor by teleporting on Forge Spirits (Beware backdoor protection)!  Consider stacking ancients with Forge Spirit.  Rune spawn is random, therefore, before the rune spawn, I like to send a Forge Spirit to destroy bottom rune at the 46th second and grab top rune at 55th second (during lane phase).  Push lanes with Forge Spirits or scout with them.  You could also pull incoming creep wave away from tower with a Forge Spirit; you can now attack the tower without enemy creep. Cold Snap has 1000 range, but Invokers attack range is 600.  If Quas is low level, cast Cold Snap with a distance around 300 or your next attack will not trigger Cold Snap because it will be on cooldown.  As Cold Snap is leveled up the trigger cooldown decreases, meaning that at maximum level of Quas heroes with cast or attack animations above 0.2 seconds are unable to do anything without dispelling the debuff first, if the mini-stun procs immediately when it is able to.  Most of the time, it is a good idea to use animation canceling during Cold Snap's duration.  Aphotic Shield and Living Armor counters cold snap hardcore. Level 1-2 Cold snap no longer cancels Salve/Clarities. Damage over time spells works wonders with Cold Snap.  Note: the stun only triggers on damage greater than 10 after reductions (creeps does not trigger cold snap against heroes with high armor).  Urn of Shadow triggers Cold Snap. If Ice Wall deals 10 or more damage after reduction, it will trigger Cold Snap.  Ice wall with two or more Exort will remove Templar Assassins refraction every second.  Casting ice Wall in front of your tower can provide a great defense.  Although opposing heroes are unlikely to be caught, you can destroy all the creeps with tower and Forge Spirits.  Ice Wall does not necessary have to catch any enemy.  You could use Ice Wall to block reinforcements. Meteor provides a small vision; Cold Snap quickly!  Meteor with one level of Exort can be used as a scare tactic (Do not consider this without Aghanim's Scepter.).  Meteor can also be used defensely; opponents will reconsider chasing you when meteor is following you but remember Chaos Meteor has the longest cooldown out of all of Invoker's spells.  Be careful about when you cast it, as you have to wait almost a minute to cast it againBesides your team carry, Alacrity on Forge Spirits or siege creep is a great way to push towers from a distance.  Make sure to put Alacrity on Void.  Alacrity can be cast on targets with magic immunity!  In 6.85v Update, Alacrity attack damage and attack speed got buffed from 20/30/40/50/60/70/80 to 30/40/50/60/70/80/90 so consider this spell as one of your best spell in game as it can give tons of damage if used on your team carries (right clicker)Ghost walk can dodge certain projectiles.  Invoke interrupts TP scroll, but Ghost Walk does not.  Ghost Walk's slow aura is blocked by magic immunity.  If your goal is to run away from the enemy, remember that you need at least 4 levels of Wex in order to negate the movement penalty.  However, if you have time, it is also advised to shift all of your active orbs to Wex, in order to grant yourself a movement speed bonus. Ghost Walk, Force Staff, and Ice Wall can be used as a great initiation tactic.  Imagine this:Your team is pushing, but have trouble taking tower uphill.  You can use Ghost Walk, wait for target to last hit creeps, then force staff target out of position then Ice Wall!This spell can push opponents on/off cliffs.  If you invoke Meteor with EEW, a simple QR can invoke Blast after invoking Meteor.  If you cast Sun Strike behind an opponent, but he does not run back, you could push him/her towards Sun Strike.  Blasting an opponent can break trees if he/she backs into it. Deafening Blast can also be used to "PULL" targets!  Use Tornado or Eul first.  If you time it properly and your target lands on Blast, they will get pulled towards you.  However, this is probably one of the hardest things to do in Dota. Works great with Eul's scepter or two second stuns by allies.  If someone is using TP scroll with low health, but your Sun Strike will not hit him/her before he/she TP, then target near the fountain instead.  Bloodseeker may discreetly guide your Sun Strikes with vision.  Sun Strikes provides XP if you kill the hero with it!  If you are running back to fountain, consider using Sun Strike to farm a creep or two or hurt enemy hero.  Sun Strike pierces through magic immunity. Weakened by Arcane Boots and Obsidian Destroyer's Essence Aura.  Do not focus Wex build if you predict three or more opposing heroes will get Arcane Boots.  You can lure opponents out of position with EMP.  Casting EMP in fog or directly on the tower might conceal your spell. While it loses much of its potency in the late game due to mana pools getting larger, EMP can still greatly disrupt enemies at all stages of the game.  Destroying the mana on low-intelligence heroes, particularly strength and agility casters, can render them impotent in the early- and mid-game, while doing so in the late-game can hinder an enemy carry's ability to cast spells