Those SZeta are using MCA, I believe. SZeta's a pretty good candidate for MCA.
For most players, SZeta is played as a range rock. For his melee, he takes a long time to complete the 5 hits, which has both good and bad points, but more towards the bad side. Custom points mostly goes to Spec to abuse his skills.
AS Qubeley is too damn costly to build. I suggest you build Aegis first.