I just played for a very long time that's all.
My dark grid (and everything else not Light) is mainly event weapons with 1 or 2 0~1LB gacha hime weapons and hardly any + on them. Almost all my + and $ resources went to my Light grid.
Check my earliest post in this thread (That particular long winded one) in case you haven't already done so. The soonest Light event you can look forward to is Barong raid. That event gives you a very nice Atk L gun. As for Barong herself, while her stats are indeed terrible, she's still better than Houou. And since it's a raid event, you can prolly farm for an extra set of guns. Just be mindful that the raid event itself is among one of the more annoying ones so farming tickets will be quite painful. The next thing you can look forward to is the Walkure Romanze Collabo spear. It's another Atk M / Hp S just like Sphinx Hammer.