1. Gear and Setup
You might struggle with Black Tiger if your power is below 1.8 million.
Having the Skull Ring is good, but if you don't have it, go for Cursed Set (4 pieces) + Black Tortoise Set (4 pieces) (Attack options).
Min Byung-gu: Equip Blessing for the Takeout effect.
Kyoto Ryuji: Desire is good to have, but Greed is also fine.
Shadow: Crit-related gear, use Igris.
Black Tiger: Can't get the 5% attack power effect due to fire-type monsters, having a level 15 dark-type gear is good.
Having a Chase Attack Chip is good, Anti-Crit isn't that important, recommend Damage Increase/Crit Damage Increase chips.
2. How to Beat Floor 70
Start by stacking 10 stats with Kyoto Ryuji (5 stats with Q skill).
After using Q, switch characters, summon Black Tiger and deal damage with normal attacks.
Black Tiger is a percentage damage dealer.
Breakers appear below 60%, use skills before switching.
When using Break, use Q, press 1 to switch, then use Q.
Min Byung-gu appears with QT, use E, use Ultimate, press 3 to switch to Black Tiger.
Shadow is summoned below 20%.
When small monsters appear, switch and use Q skill, utilize Kyoto Ryuji's Ultimate.
Consider Min Byung-gu's skill cooldown and switch before the 2nd cycle (Blessing effect).
3. Wrap-up and Guild Promotion
If you have good control, you can get 3 stars with lower stats.
DK Guild is recruiting members for Guild Boss/Total War.