Mysterious Portal

Type	Spawner
Environment	Old One's Army
AI Type	Mysterious Portal AI
Damage	0
Max Life	5
Defense	20
KB Resist	100%
Immune to	All debuffs
Hurt	https://terraria.gamepedia.com/File:NPC_Hit_1.wav
Killed	https://terraria.gamepedia.com/File:NPC_Killed_1.wav
Open	https://terraria.gamepedia.com/File:Dd2_etherian_portal_open.wav
Idle	https://terraria.gamepedia.com/File:Dd2_etherian_portal_idle_loop.wav
Spawn enemy	https://terraria.gamepedia.com/File:Dd2_etherian_portal_spawn_enemy_0.wavhttps://terraria.gamepedia.com/File:Dd2_etherian_portal_spawn_enemy_1.wavhttps://terraria.gamepedia.com/File:Dd2_etherian_portal_spawn_enemy_2.wav

I don't see why we can't just blow up those portals.
— The Demolitionist

The Mysterious Portal instantly opens at the start of the Old One's Army event. The Mysterious Portal cannot be destroyed, and two of these will spawn 235 tiles on either side of the Eternia Crystal Stand. They are responsible for all the enemies that spawn in the event, and they despawn upon the event's completion or failure.

Tips[edit | edit source]

A good way to keep the enemies at bay near the Mysterious Portal is by placing an Explosive Trap near the portal's entrance. This way the enemies will instantly take damage when they come out.