Um well vessel for the slayer of god but meh on my part. ^_^ Why not put in an SRW game? You get to solo the entire thing with one mecha and forget about strategy.
You mean like what happened when Dann of Thursday got added to the roster? Well, it's not like Weltall being over powered will be anything new considering many others that have been part of SRW (God Gundam, Genesic GGG, Zeorymer, several originals). It is a wonder though that it hasn't been added yet considering KOS-MOS was added into Endless Frontier.