Tips

• Illusions will copy whatever orb configuration your hero has when they spawn. With the "Elitist" facet, they can lifesteal from Quas orbs and move faster with Wex orbs, but they do not apply the Exort spell amp debuff on attacks.
• Cold Snap has ridiculous range. Use it to cancel consumable health regen on the enemy mid from a distance if you have vision of them.
• Urn of Shadows on an enemy can trigger a Cold Snap every second.
• Pay attention to what your teammates are doing before you Tornado in a team fight. It's a great spell and all, but it also has Naga Sleep levels of ruining teammate spells.
• Tornado serves as a basic dispel which allows you to remove most buffs off enemies including runes.
• You can stack certain neutral camps with Tornado. This only works on some camps, however. The reason is because Tornado raises the creeps above the spawn box check height, but different camps have different heights. You'll have to test it in a lobby yourself (use the -spawnneutrals command with cheats enabled) to see which camps work and which ones don't.
• Tornado prevents targets from being attacked. This means towers can't aggro units that are being Tornado'd. You can leverage this to force the tower to swap aggro to a hero by Tornadoing a creep wave, but not the enemy hero in tower range.
• You can use Tornado to potentially kill enemies affected by Oracle's False Promise. False Promise can't heal targets if they're banished. So if you Tornado an enemy right before False Promise times out on them, they'll lose False Promise damage negation while in the banish, but won't get healed until they come out. Therefore, you can kill the enemy with Tornado's landing damage before they get healed.
• I remember Alacrity's spell combo because every time I cast it, it's time to lay the W-W-E Smackdown SHUT YOUR MOUTH.
• Alacrity can be cast on creeps, siege creeps, and summons (like Forged Spirits).
• Forged Spirits are invaluable for pushing. They have amazing range late game, serve as two extra damaging and tanking units, can cut off the creep wave, and they last forever.
• Forged Spirits are also great if you're mid to serve as rune control. Cast Forge Spirits around 20 seconds before the even minute mark and have it sit at the rune to kill it.
• Ghost Walk is QQW. I remember this because every time I get ganked I want to QQ... W.
• Ghost Walk HP/mana regen is disabled if you've taken player-controlled damage in the last 3 seconds.
• You can cast Ghost Walk while channeling a TP.
• You can change orbs and cast Invoke while invisible or while channeling.
• Ice Wall can be surprisingly effective in the mid lane matchup. If someone's making a move on your high ground and you're trying to shake them off, you can potentially get even more return damage by casting Ice Wall instead of Cold Snap.
• With practice, you can lay Ice Wall perpendicularly to catch escaping enemies.
• The disarm of Deafening Blast can only be bypassed by activating debuff immunity/BKB. If you hit an enemy with it, they can't take off the debuff even with a strong dispel like Abaddon's Aphotic Shield, they can ignore it by activating BKB. The knockback can't be dispelled by anything.
• Sun Strike is useful for more than just sniping low HP heroes or comboing with Deafening Blast. Scoop a ranged creep last hit in the first creep wave or later in the game when you're just chilling regening in the fountain. Use the vision to scout out Rosh, runes, or jungle stacks.
• Tormentors damage whatever hero hits them globally. If you're trying to escape enemies at critical HP, a big brain play could be denying yourself to a Tormentor by Sun Striking it.
• Blind Sun Strikes are always hype, but you can consider using your team's Scan to assist with the timing.
• Sun Strike damage fully pierces debuff immunity/BKB.
• The "Agent of Gallaron" facet's Agh's Scepter Cataclysm can be useful to locate enemy heroes in the late game, similar to how a Zeus would casually use Thundergod's Wrath for vision. This is highly relevant if you suspect the enemy team has Smoked.
• Learn and practice the stereotypical Invoker combos: EMP+Tornado, Forge Spirits+Cold Snap, Chaos Meteor+Sun Strike+Deafening Blast, Forge Spirits+Alacrity, Tornado+Sun Strike.
• Despite its appearance, Agh's Shard EMP is not classified as traditional "forced movement," but rather a "pull." This means it can't interrupt things like Magnus's Skewer, Phoenix's Icarus Dive, Primal Beast's Onslaught, Spirit Breaker's Charge, Techies' Blast Off, or Templar Assassin's Meld.

Counters

• Always keep tabs on the spells he has Invoked by clicking on him to get a better idea of how he's building. If you're mid and he has Sun Strike invoked, warn your team. If he's missing and he's been going Q/W, tell them to watch out for a Tornado from the trees.
• Try to remember he has Sun Strike BEFORE you think you narrowly escaped the first gank of the game, rather than after.
• Heals from items like Greaves, Mek, or Magic Wand are applied before Tornado damage takes place allowing you to survive potentially lethal Tornadoes. Casting Pipe's barrier may allow you to Blink out of a low-level Tornado when you land.
• Forged Spirits burn off your armor with each of their attacks. Invoker isn't just harassing you just to be annoying. Well he is, but he's also trying to soften you up for any follow up right clicks.
• Remember that Sun Strike damage is split evenly among all targets hit. If you think an ally is about to die to Sun Strike, stand next to them to diffuse the damage.
  • This is especially relevant in the mid lane. If Invoker is trying to kill your range creep with Sun Strike, it's usually worth tanking some damage so he doesn't get the last hit.
• For the love of everything, please bring some sort of detection (Dust or sentry wards) when trying to gank Invoker. Ghost Walk is not a good escape, dude needs several points in Wex just to not slow himself.
• Faceless Void's Time Dilation will calculate its debuff for all of Invoker's spells that are on cooldown, even if they aren't actively invoked.