Hello!! I'm KaiserXVI
I use Tamarinne/Achates/Kawerik/Landy as a guideline.

Because this week the conditions hinted that you can have 2 main-DPS heroes and you have to use only RGB heroes (thanks SG for thinking this for new players).

One - Front row should be Soul weaver (with AOE skills) I think Tamarinne is the best choice.
Second - Back row should be a hero with strong DPS in S1 I choose Landy to benefit from the ATK bonus of her skills.

For support heroes, I use Kawerik to deal with minions by following the condition that you can kill them with "provoke", "redirect provoke" or "silent" debuffs. You should also pay attention that the debuff should not come from a single attack skill.
Achates is always the best choice for me for healing damage because she can remove all debuffs and heal my whole team.
And most importantly, she can rotate skills forever that help your DPS can deal the best damage.

Status and Strategy: I hope you watch my video that can explain better.

How to exhaust the boss
You need to kill its minions when they pop up. After 2nd turn of the boss turn and before they attack you at that time. (their attack is too high damage.)

Because you have 2 main DPS, you should let them take turns dealing damage to make Tamarinne much easier because Tamarinne's AOE skill increases the CR of the back row heroes by 50%

For Kawerik I think you should build with low speed and use War horn artifact only to push his CR.
For Achates I recommend you use proper speed, not Full speed because Kawerik that's why.

Replaceable heroes

Tamarinne -I don't know.!!
Landy - Wukong/Luna/Ram/etc.
Kawerik - Senya/Yufine/Cecilia/etc.
Achates - Mascot Hazel(if you use Kawerik)/Schniel (not sure)/etc.

Whatever, you should try it and adjust it several times for your goal.
good luck.