Wrathful Staff Refinement on -Atk/+HP Bridal Lyn?

Hey guys, I’ve had a +HP/-Atk Bridal Lyn who I’ve been quite satisfied with until now, but I’m still hell bent on using her as my main support healer. However, I’m not quite sure on whether I should invest in her attack despite the -4 bane and refine her weapon with Wrathful Staff for extra chip damage or refine it with Dazzling Staff and replace her B-Slot with another skill.

I would appreciate any advice you guys have to offer, and thanks in advance to whomever replies, cheers guys!