Ok, I got to a point where battles are fucking unfair. The rivals have more than 800 hp, and you with work make 10 or maximum 25 (of course if we take out the letter that makes 50) so... What do you recommend?
Arena inside has a sort of black market NPC at night time where you can pay some height for a hp booster I believe it's called. At the end of day every day it will permenantly boost your hp by 5. If that isn't enough for you then there's succubus decks which have buffs that steal hp from the enemy and whatever hp they steal through those buffs is granted to you as permenant max hp allowing you to gain far more max hp than the hp booster could ever hope to give you. Thanks to succubus decks my character's max hp growth has outpaced all the enemies.
Find the cards with permanent scaling, infinite scaling, or % damage. So for 7.9, that I'm aware of:
GLA: Gladiator's Cunning, Freya The Slayer
FAI: Fairy Fire, Fairy Witch, Fairy Finale
DRK FAI: Augmented Corruption, Dark Fairy Queen (questline)
MACH: A.E.R.A./E.L.U.N.E/Upgrades (questline)
ZOM: Hooded Corpse, Zombie Swordmaiden, Xhelzus The Necrotic, Everlasting Zombie
SUC: Belial The First, Zekari Massacre Specialist (questline)
GAM: Poker Face, Snake Eyes
SPACE: (Elite) Space Force - Athena, (Elite) Space Force - Arabella
GAL: Galactic Hive-Mind (token), Galactic Size Mage, Galactic Doombringer
DEMON: Demonic Decay, Blood Pact?
PARA: Parasitic Magus, Yogg'Saron Parasitic World Eater
COV: The True Witch (multiple cards), Creeping Miasma
CULT: Ritual of the Goddess (Baal questline)
VORPAL: Izel - Ultimate Warrior, Vorpal cards in general
OTH: Devorah The Insatiable