Nullifier

So, most defensive items in Dota 2 function as a single protective event—Ghost Scepter gives you 4 seconds of physical immunity, Aeon Disk fires once and gives you 2.5 seconds of invulnerability, and Glimmer Cape lets you or an ally go invisible. These are clean answers to clean problems, and the game is balanced around the expectation that the hero using them gets that protection.

Nullifier's entire purpose is to make that expectation wrong. You fire it at a target, and for the next 4 seconds, every defensive buff they try to apply — every item they try to activate, every ability that grants them evasion, phasing, invisibility, or damage immunity — is stripped off them every 0.2 seconds. Not once. Continuously. Twenty times across the duration. The Ghost Scepter goes off, Nullifier strips it, and they are physically damageable again in the same second. Aeon Disk fires, and Nullifier strips the Combo Breaker buff—the damage immunity does not happen. Glimmer Cape goes invisible, and Nullifier dispels it—they are visible again immediately.

The debuff itself also cannot be dispelled. A hero with Nullifier on them cannot use a Manta Style, a Dark Pact, an Aphotic Shield, or any other self-dispel to remove it. They are locked in the stripped state for the full 4 seconds, their defensive toolkit neutralized by a debuff that refuses to be removed in return. Against a support who has invested their entire utility budget into keeping the carry alive through dispellable buffs, Nullifier is a direct line to "Their investment does nothing."

The flat +75 attack damage on top of everything else is also quietly excellent. For a right-click carry building Nullifier as a situational item, that is a meaningful late-game damage contribution on par with a standalone damage item—you are not purely sacrificing offensive power to buy the dispel utility; you are paying 4350 gold for both simultaneously.

Late game, situational—fourth or fifth item on physical damage carries who are hitting a specific defensive wall that lower-cost dispel options cannot breach. Phantom Assassin, Ursa, Slark, Anti-Mage, Windranger — heroes with high attack speed or burst who are being specifically countered by one or two defensive items the enemy team is leaning on.

The draft signal is a defensive item stacking against you. If their carry is winning fights with Ghost Scepter into Force Staff while your team's right-clicks bounce off ethereal form, Nullifier solves the problem cleanly at 4350 gold. If their support is chain-applying Glimmer Cape to keep carries alive through your burst window, Nullifier strips every application continuously. If they are specifically building Aeon Disk to survive your burst pattern, Nullifier hits Aeon Disk on the way in and strips the Combo Breaker effect immediately.

Where you skip it: against enemy heroes with no defensive item actives. If the enemy carry is building pure right-click damage—Desolator, Daedalus, BKB—and has nothing dispellable worth stripping, Nullifier's active does nothing. You are paying 4350 gold for +75 damage and +10 armor, which is a fine stat package but not what you are buying the Nullifier for. Against those lineups, a dedicated damage item closes games faster.

Also think carefully against Linken's Sphere. Nullifier's projectile is not blocked by Linken's Sphere—it is not a targeted single-target spell in the traditional sense—but check the specific interaction if you are unsure. And be aware that Lotus Orb specifically is a trap: if the enemy has Lotus Orb already active when you fire Nullifier, the Nullify debuff can get reflected back onto you. Fire Nullifier before Lotus Orb is cast, not after.