She cannot perfectly counter some troops that the Witch can as the Night Witch cannot distract ground-targeting troops with her Bats. However, the Night Witch can defeat nearly all cards that cost 6 Elixir or below, like Sparky, Lumberjack or Wizard.
She can't attack air so Minions or Baby Dragon will be effective at taking her out since they can easily take out her summoned Bats. However, you will need to make sure your air troops do not target anything tanking for the Night Witch or else the Bats may defeat them.
Splash damage ranged troops like the Executioner, Wizard, or Witch are very effective against the Night Witch since they can defeat her and her spawned Bats quickly without receiving much damage.
Bats are fairly weak when alone by themselves. But if left to accumulate behind a tank, they will melt through defending units due to the rising DPS. If enough build up, they can even kill swarms in a matter of seconds. Because of this, Night Witch is best used behind a tank. The Bats can also distract and destroy an Inferno Tower, although it is still recommended that you bring a Zap/Lightning to reset the Inferno Tower.
To counter a Night Witch push it is ideal that you have strong ranged defence, a spell and high DPS or burst damage to kill the Night Witch. An Executioner is an ideal example of this, because he can target the Night Witch and her bats with his huge area damage.
Pairing the Night Witch with a Miner is a strong synergy, since there are two outcomes. The Night Witch gets killed and the spawned bats are tanked for by the Miner while the Bats that spawn from the Night Witch's death will deal massive damage to the arena tower if left ignored. Or the Miner tanks for the Night Witch and her bats, forcing the opponent to react or suffer massive or maybe even lethal damage.
A Poison is effective for taking out a Night Witch. If timed correctly, not only will the Poison cripple the Night Witch, it will also eliminate all the spawned Bats. If it destroys the Night Witch then it may also destroy the Bats spawned on death.
Due to her Tombstone-like ability to burst into 2 Bats upon death, any troops that killed her could also then be wiped out by her bats spawned on death, preventing a counter push.
Just like the regular Witch if the Night Witch summons while under Rage, her bats are also affected. Keep this in mind when going on the offensive.
The Night Witch can be used to effectively counter the Graveyard since her Bats can defeat the Skeletons rapidly.
A Night Witch, with the assistance of your Princess Tower, can counter a Balloon. Even though the Night Witch herself doesn't attack air, her Bats are enough to stop a Balloon from reaching the tower.
The Night Witch card was added to the game on 31/5/17.
The Night Witch was once available in the Night Witch Draft Challenge which started on 29/5/17. In this challenge, gameplay was similar to a regular Draft Challenge, except that one of the players was able to choose who would use the Night Witch. If the player achieved 12 wins, they obtained the Night Witch two days early. However, this was not exploitable like the Electro Wizard Tournament as the Night Witch Draft Challenge had one-time rewards.
On 12/6/17, a Balance Update decreased the Night Witch's Bats spawned by death by 1 (to 3 from 4), increased Bat spawn speed by 1 sec (to 6 seconds from 5 seconds), and initial Bats spawn slower.
On 11/8/17, a Balance Update decreased the Night Witch's damage by 9%, her range by 11% (to 1.65 from 1.85), her Bat spawn speed by 1 second (to 7 seconds from 6 seconds) and the number of Bats spawned on death by 1 (to 2 from 3).
Unlike the regular Witch, her attack is melee, doesn't do area damage, and she can't attack air.
The Lava Hound, Golem and Night Witch are the only 3 troops to spawn troops after death.
The Night Witch is ranged and does splash damage in Clash of Clans.