Oh, I remembered that one, actually. What I forgot about was the M2456s (the other gold-based laser gun): I've never seen anyone use that thing because it's so overshadowed by the Nova o__o;
I got the best assault rifle. it is quite good in lair survival... and requires less energy than most guns
How long does it feel useful for? I thought the enemies get tougher fairly quickly... Also...anyone wanna take bets on how long it takes to kill Mantis in single player?
Bug-squishing. Try hitting it with both railguns, a hyper clip and the Thunder ability when you're fighting it solo. I thought that thing was meant to be a boss, but I guess it's just a giant bug afterall o__o;
"Liselotteaiko" already demonstrated that two-shotting Mantis was possible on YouTube before me. Consider this more a demonstration of how fast you can make it die with weapon switching
From memory, I got it within two weeks. I had enough time to make each boss drop mithril twice every day when I was grinding for it, and the longest it should take you is about 19 days. Felt more like 12 or 13 for me. Upgrading it, on the other hand? Good lord, was THAT a drag =.="