Etherian Wyvern

This one only appears inside the Old One's Army, and never on its own. Which waves bring it depends on the tier you are running: tier one holds it back until the closing waves, tier two throws it at you across most of the event, and tier three brings it early then drops it again. Its appearance and stats scale with the tier, so the tier three version is a different problem from the one you first met.

It can also arrive outside the normal wave schedule. Betsy calls in a flight of them with her roar, so even a clean run at the final tier can turn into a wyvern fight at the worst moment.

It ignores terrain completely. The pattern is to climb well above you or the Eternia Crystal, pick whichever is closer, and dive. The climb buries it inside the ceiling, so for most of its cycle it is sitting in solid rock where ordinary weapons cannot touch it, and it only becomes a target during the dive itself. You get a screech as the tell, and the dives come round fast enough that there is little idle time between them.

Sentries do not cover this gap. Ballistas shoot flat and the wyvern spends its life either overhead or inside a wall, so a defense built purely on them leaks wyverns straight onto the crystal while you are busy elsewhere.

It is not segmented and does not use worm behavior, so the tricks that work on the usual sky wyvern do nothing here. Treat it as an oversized bat that phases through the map.

Anything that reaches through blocks, or anything you can point upward with range. Melee is the awkward case in tier one, because most swords available before Hardmode project nothing past their own arc and simply cannot reach a target sitting in the ceiling.

• The Ice Blade and Enchanted Sword both throw a projectile out of the swing, which is enough to answer it with a melee loadout.
• Yoyos travel far enough on the string to catch it mid dive.
• Boomerangs cover the same gap and come back through the dive path on the return.

If you are playing ranged or magic this enemy barely registers. It is specifically a melee problem, and one worth solving before you start the event rather than during wave four.

Its banner needs four times the usual number of kills, so it is not something you finish by accident on the way to beating the event. Farming it means running the heavy wyvern tiers over and over.