Disclaimer: I am just a filthy casual. This guide is meant to get you through Ragna Break and get all the rewards offered by it as a f2p.
LV.40 Boss: Customized Laufey | A Lullaby for the Dark Prince
Team composition is tricky. I managed to beat Lv.1-37 without any major issues but Lv.40 became tedious and quick. It took 4 attempts as the boss has over 9 million HP.
Newbie Mona is critical to sustain you through this fight as she supplies your allies with vampirism. Any other healer will be punished with DOT (Damage Over Time: Venom) which can't be cut but can be cleansed by Pomona. I didn't have the luxury of Pomona before I started Ragna so I've mostly used Newbie Mona to get me through. Kind Leo is another supporter that has been vital as he provides your allies with Skill Charge Gauge amount, Weak Point Skill Final Blow and barrier. Thisbe can be used as a puller to replace Chang'e as she also nullifies debuffs on her Tap skill. If you don't have Thisbe, make use of Chang'e. Without a proper healer, speed will be your most valuable asset. An ignited attacker such as Serket or Eve are required if you plan to deal massive damage. Justice Mafdet or the newest Child Virupa are also excellent choices. If you don't have an ignited attacker, use Virupa or your highest attacker. Aimless Pantheon can supply extra support by providing your units with CRT. To bypass Laufey's Time Debuffs, you can use a supporter such as Maid Sytry for her Time Twist or Virupa for a 75% chance of Time Twist. Be advised that without the necessary uncaps and the lack of a healer, Maid Sytry won't survive for long and you'll find yourself back in a sticky situation.
Not having Pomona isn’t the end of the world. An underrated unit, Cute Euros can cleanse and counter DOT by transforming it into heal. Set her skill queque on: S (Slide) as it has a 75% chance of nullifying disable debuffs for 3 Water allies and her drive Chocolatier heals 2335 HP and removes debuffs from 3 allies. Cute Euros can successfully deal with Death Heal and Dot: Venom, bleed, etc. and has kept my units alive until the timer ran out.
Ideally, you want your drive order to be: Patheon > Euros > Leo
Another popular supporter for this Ragna is School Swimsuit Davi who is able to grant your allies Double-Edged Sword (ATK UP/DEF down and Slide Skill Damage +1250 for 5 Water allies.
Newbie Mona’s vampirism tactic requires a bit of planning. You need to set her skill queque to: S T as DOT needs to be triggered before it can be cleansed.
Below are the stats of my units:
Newbie Mona lv.60 +2/ Kind Leo Lv.50 +3/ Serket Lv.60 +3 Ignition:11/12 / Aimless Pantheon Lv.60
Virupa/Pomona/Thisbe/Cute Euros Lv.50
Update: I managed to ignite Serket fully and went for a safer approach that takes 4 mil. per round consistently.
Virupa | Leo (Leader) | Serket | Pomona | Pantheon
Drive order: Pantheon > Leo
My final team composition (very risky/inconsistent damage) is: Virupa | Leo (Leader)| Serket | N. Mona | Pantheon
Virupa needs to be set to Tap as her bonus damage in Luminous Mind only activates when you have a time-based buff. N. Mona (as mentioned earlier) needs to be set to S T to trigger Laufey’s DOT and cleanse it. You will use Leo’s Slide mostly for his Barrier, Skill Gauge Charge and Weak Point Skill Final Blow. Serket or any other ignited attacker you own needs to be set to Tap or Slide respectively. I keep Serket on S. Finally, Pantheon also needs to be on Slide to provide CRT rate and Critical Damage.
Drive order: Pantheon > N. Mona > Leo
Damage: 4-5 million per count.
Armor, weapons and accessories are also important to your survival. For Soul Carta, I mostly used ATK/DEF or HP/DEF. I had nothing specific for raids at my disposal.
A bit of my personal thoughts: Compared to the old Ragna Break we had, this one was very stressful. Laufey is equipped with all sorts of bs skills (compared to the lackluster Child version) that target nearly your entire team and the rewards are only half worth it. I saw many players frustrated and struggling and got added by many players to kill off their Lv.40 bosses. The enthusiasm I felt over this Ragna Break was short-lived with the exception of the Raid Story which was well-prepared, kept my attention till the end and didn't feel rushed at all. As an extra note: Virupa has an interesting kit and in my opinion is worth pulling.
03/25/21 Update: Ch 3-2 Les Miserables was added to Story. Dungeon IV. Electric Pathos - Stage 8 gives out 520 Exp.