i dunno... ive ever only found one to carrier without some kind of event going on, and ive logged over 4000 npc kills. not alot, but enough to at least have found more than 1 under regular circumstances. the other six carriers ive gained have been either from artifacts or during events where rares are more common than normal. whereas ive found 3 or 4 blade harvesters over the course of an hour, and ive heard other players have done much better than that.

just got my second. think i killed around 200 NPCs to find the two

I killed probably 75+ NPC and not seeing any, so I m starting to think even it may be random... probably best to get more Embattled Retreat mission going. Since there's 15 repeated completions, you probably won't see all 4 Octafari Leviathan Rift-Emitter if you only had 1-2 Embattled Retreat mission completed.

So I m focusing getting 5-7 of those mission completed before hunting for more Octafari Leviathan Rift-Emitter

I didn't even started the mission so I doubt that's it. It's just random, as usual.

got 2 in like 20 kills. rank 82

Nice... and lucky.

I've now spent 12300 energy on fighting NPC's in the last 3 days (4 levels and 2 Tri-Matrix Emblems). No sign of a Leviathan yet. I'm starting to wonder if this is an elaborate hoax. There's no way that they're only uncommon. They seem more like mythical rarity.

i got 2 and i havnt killed a single npc other then the leviathans thats poped up
i think the lower the level the more common they are this time X-D im rank 95

got my second not 2 minutes ago, not bad, at least it isnt as crazy as the previous mission

find and disable 4 uncommon npcs in 2 weeks
find and disable 80 common npcs in 2 weeks and end the mission costing 25 energy per round

I got my 4th yesterday ;P

Done 4, then finished off the mission. It's a nice little attack boost, don't care about the mission building drop.

I'm level 320 when I started. I'm now level 324. I've burned almost 10k energy racked up 2000 kills and seen one of these freaking things. I've found two hypergrids one command nexus, two stalars, two regnars and god knows how many uncommons.

This thing beginning to make me angry.