The Ancient Sentry is a promotional unit released during the 6th Invasion Competition, available July 11-15, 2014 for 69. It was re-released for one day on June 23rd 2015 for 52 as part of the Breaking Into the Vault! sale.
The Sentry Shielding attack hits each of the three squares in front of the sentry and does splash damage beyond that. The total damage can be significant. The laser attacks can be very powerful in PvP.
Since the Sentry is a Defense unit, it can occupy defense-only unit slots in the player's formation. It is the first defensive unit that is not ignorable, meaning that the battle will not end if one side has only a Sentry left on the field.
Up to four Ancient Sentries can be used in the same battle.
Defeat the Ancient Sentry shooting up the Outpost!
Reward:
500
Dialogue
Start mission
LT! LT! I visited an Ancient archaeological dig with Percival, and I found this neat Ancient sphere! He let me keep it!
Did he? Obviously Percival hates us and wants us dead.
Aw, c'mon, LT, Percival said that the activation protocol was lost ages ago. Besides, it's just a neat gizmo — what's the chances it's some kinda superweapon? It's perfectly safe!
I'm gonna go ahead and muster the troops now.
Finish mission
Oops.
Okay, "oops" doesn't even BEGIN to cover it this time. On the other hand, that thing was pretty badass. Any way you could repair it, so it can kick our enemies' butts instead of ours?
Yeah, I think so. But it uses so much energy, you wouldn't be able to have more than four in any one battle.
Small price to pay. Well, Zoey, it looks like your reckless disregard for safety's actually worked in our favor this time. Kind of.
Zoey? Did you guys bury some metal pipes in the ground near the beach? This definitely doesn't look like a treasure chest…
What in the heck are you kids talkin' bout now? OH! Yeah, guys, you should move away from that before you wake it up…
Oh no! It's moving! What happened?
Finish mission
First, large explosions! Then, you find robot monsters and somehow activate them! I'm not usually one to put my foot down, but you kids are officially banned from playing on this beach. I don't know if the Outpost can take much more.
But! We didn't mean to! It was an accident!
Yeah, LT. They didn't mean nuthin' by it. It's a good thing they found this stuff when they did. What if those things woke up when we were all sleepin'?
Reward screen
Ok fine, but you have to bring a full platoon with you next time.