Naga Siren vs Necrophos

How this matchup plays

Trying to swarm a teamfight with illusions runs straight into everything Necrophos wants to do. His Heartstopper Aura constantly damages every unit around him, which means all of Naga Siren's illusions are always taking a little bit of damage. This makes them easy to identify and clear out with a single Death Pulse, stripping away her main farming and fighting tool. Necrophos thrives on slowly grinding enemies down, and Naga's army of low-health copies simply feeds his game plan. The constant decay from his aura makes it impossible for her illusions to stick around long enough to cause any real trouble.

This advantage lets Necrophos and his team group up and push much more confidently. Naga Siren wants to split the map and force reactions, but her illusions die too quickly to create sustained pressure against a Necrophos. In fights, it's hard for Naga to hide among her copies when they're all melting away. This makes her an easy target for slows and, ultimately, a Reaper's Scythe. Naga's best bet is to avoid him entirely, get a massive farm lead, and use Song of the Siren to let her team isolate and burst Necrophos before he can establish control.