Talk:Thunderbolt/@comment-4719392-20130620152647

Maybe this will help.

http://www.reddit.com/r/Warframe/comments/1fwen5/defense_rewards_updated/

Thunderbolt is a tier 3 infested defense mission reward, with a 2% drop chance. So unless DE changed it (I saw that link over a week ago), any defense map has a chance to drop it.

Reading the comments, it appears tier 3 rewards start on wave 5 on both Palus (Pluto) and Xini (Eris), though this is probably valid for all the defense maps in Eris.

For those only looking for the mod, I recommend going to Palus. The enemies might be a little stronger there, but the waves there are MUCH shorter compared to Xini (lower amount of enemies). A single World on Fire from Ember or Sound Quake from Banshee is enough to clear most, sometimes all of the enemies in the wave.