Luna/Counters

Bad against...

 * Blade Fury and Omnislash both dodge Eclipse.


 * Innate high magic resistance from Berserker's Blood and long attack range coupled with Burning Spears makes it difficult for Luna to lane against Huskar or counter Huskar's Life Break effectively.


 * Heavy nuke damage and disables can render Luna completely helpless in fights earlier on.


 * Several damaging nuke spells on low cooldowns. Thundergod's Wrath can be used before a fight to harm Luna before she activates her Black King Bar, reducing her survivability for that fight.


 * High nuke damage. Laguna Blade can also be upgraded with Aghanim's Scepter to bypass Luna's Black King Bar.

Others

 * Sand King
 * Chaos Knight
 * Slark

Items

 * Pipe of Insight
 * Shadow Blade
 * Glimmer Cape

Good against...

 * Lucent Beam can interrupt Black Hole from a safe distance.


 * Lucent Beam can interrupt Fiend's Grip from a safe distance.


 * Lucent Beam can be used to interrupt Death Ward from a safe distance.


 * Moon Glaive bounces cannot be disjointed, and Luna's nuke damage is plenty enough to nail down Phantom Assassin.


 * Lucent Beam and Eclipse can be used to help Luna's ally win a Duel, and Lunar Blessing can help with Luna winning Duels herself.

Others

 * Nature's Prophet
 * Undying
 * Lone Druid

Works well with...

 * Combined with Lunar Blessing, Precision Aura allows Luna and her allies to deal a great amount of damage early game


 * Vengeance Aura can greatly improve Luna's attack damage in the late game. Early-game, she can set up kills as well as swap Luna out of a sticky situation to potentially save her life.


 * Arcane Aura allows Luna to spam Lucent Beams in the early game, as well as slow and disable foes to help chase them down or flee from them.


 * Track can help Luna pursue enemies and gain more gold from killing them. Additionally, upgrading Eclipse with an Aghanim's Scepter can allow Eclipse to follow an invisible Bounty Hunter, sowing chaos amongst the enemy forces.


 * Repel can allow Luna to build items other than a Black King Bar. Additionally, Purification can help her in one-on-one engagements due to her short range, and Guardian Angel can allow Luna to fight against enemy carries with little concern.


 * Eclipse causes day to become night, triggering Night Stalker's passive bonuses.
 * gives both of them a very long vision range.

Others

 * Jakiro
 * Shadow Shaman
 * Skywrath Mage

List of heroes that counter Luna, and list of heroes that work well with Luna.