Lines are quoted from the official notes; buff/nerf tags are auto-classified from the numbers and can be wrong. Covers the 14 most recent Dota 2 patches PatchMeter has fetched.
▼nerfTornadoAghanim's Scepter twister damage decreased from 40 + 10 * Wex Level to 30 + 10 * Wex Level
⇄adjustInvokeNow whenever Invoker gets Aghanim's Scepter or Aghanim's Shard, these items are inert in the inventory until Invoker activates them manually. Upon activation, he will be presented with three upgrades to choose from. Upgrades themselves for both Aghanim's Scepter and Aghanim's Shard are unchanged
⇄adjustInvokeYou can't change selected upgrades. Selling Aghanim's Scepter and buying it again will provide the same upgrade you chose the first time
✕removedInvokeAghanim's Scepter no longer provides +1 level to all three orbs. Now it provides +1 level only to a single orb you choose