I went checking your other posts in this thread so I may resonate others' points (for whatever reason, the forum's search function doesn't work, I can't even find shit). Focus on 2 abilities at most (forget ATK buffs, they're everywhere; 99% of rainbows should have them), take it easy, always work with what you got right now and finish one lineup at a time.

You may go in the direction of a "hard" counter lineup, seeing you have the best counterpuncher in Saffron and another counter in Apple (Tanabata). There's just something with Nightmaher that doesn't really click with me though (aside from her D-class stats, lack of Super Counter, no defensive buffs). Saffron gets the tank role which means Maher will only duplicate her in the same party. Easter Cactus is intriguing here. She can't support them with defensive buffs, but because "hard" counter lineups will rely on taking hits / getting hit (and consequently die faster), her ability to revive them (to 50% HP) for extra rounds of counters especially merits her use in this lineup than in other lineups. Finalize that by adding defensive support from Helenium and Anemone, the latter acting as a "finisher" with a single-target or triple-hit skill.

Getting Cactus entails committing into bringing in critical rate+critical damage+activation boosters for her as I consider her a core unit for a crit-oriented lineup, but because you already have Dusty Christmas who works best on T1 (x1.65 activation up + 100% crit during T1), adding Hollyhock and her x1.65 with CR/CD boosts is a good option for a x3.30 activation boost, making sure Dusty's skill triggers at the start where it's most deadly.

If you're still looking to complete that Kerria debuff/activation lineup, better grab Mizugi Epidendrum if you haven't.

I try not to impose my suggestion though because there are other factors out of my control (e.g. visual aspect, waifu preference). Ultimately, it's your decision to make, sooo......