Do Seraph weapons "power up" and how?

After reading a long thread I've read that Seraph Weapons "power up" from their initial stats. Some suggested that killing enemies raised their stats or damage, and a great deal of people seemed completely unable to reproduce this.

So do Seraph weapons really power up, and if so, how? Here's the thread where the rumors/hints were suggested: Seraph weapons secrets. It sounds like trolling considering the lack of confirmation reports, but I don't have a weapon of my own to test.

I've never heard of this. If i'm not mistaken, Gearbox released a update where the stats of the Seraph Weapons would be increased.

There were some complaints on how weak those guns are. Considering that there are purple weapons with higher stats, 120 seraph crystals for one seraph weapon? Not a fair trade, in my opinion. I'd do some legendary weapons farming instead.

I know there's the thrill on killing some raid bosses, but sometimes it could be very frustating, specially if you're playing solo.