A guide on how to complete story mode, how to farm efficiently, and how to gear up.
The biggest challenge in story mode starts around stage 6 or 7 up til the final stage 8. At this point, depending on how much you farmed the Chasm of Abyss and how much of the resources you gathered from that dungeon you spent, it will determine how hard/easy the final stages will be. The most important steps to increase your ability to finish the story will be Set Options, Weapon with easy +Damage Proc, Runes and Enhance Equipment. In order to do all this , you'll need to farm gold. For advice on how to farm gold, go to "Gold/Rune Farming Section". Gold is needed pay for all blacksmith interactions, buy materials, do everything.
The most important blacksmith interaction at this point will be "Carve Set Option". In this game, you can apply/rewrite set options on any equipment so if for example a weapon had "Spider Queen's Charm" Set Option, you can pay Gold and use materials to rewrite it to whatever you want. Now, you need a good amount of gold to do this because you will have to apply set options to all six equipment. 4 set bonus allows you to use a special skill that starts the game on cooldown (about 90 seconds) I believe they all have the same cooldown. 6 set increases the damage substantially on the skill.
The best set options for beating the Story (not necessarily for end game) are The Ice Giant's Frost for the 5 set Attack Buff (+80 "Damage" will be seen on stat sheet but it is actually Attack) and the Heart of the Sea Reaper for the 5 set Damage Buff (this is a percentage buff of your TOTAL Attack unlike Attack buff which is an integer buff).
Weapon with easy +Damage Proc
When you look in the store or just look through the weapons you've obtained so far, you will see that most of them have a special option that looks like this: Active upon using skill "X" or Increased damage when attacking enemies in "x debuff state". A lot of bosses have resistance to status effects later on in the game so it will be hard to apply slows, elemental Damage over Times (rupture, fire, poison, etc.) so you don't want to use a weapon that gives you increased damage when attacking enemies in debuff. Instead, you want Active upon using skill "X". You can get these weapons in the store under "High Gears". Choose a weapon that procs the damage increase off of a very easy to use and reliable to hit skill. Examples: Bart's Holy Hammer and Loki's Ki Burst (not blast).
Remember to go to Gold/Rune Farming section to learn how to farm these quickly.
If you have not unlocked R rarity boxes yet, you can buy Runes in Runes tab. Buy the A runes and just use them for now. I was able to beat the story with just A runes. I advise you to use Yellow (Massacre) runes for your main Damage, Pink (Patience) runes on a super low cooldown skill so you can lower your other cooldowns, Red (Vampire) runes on a super low cooldown skill so you can heal yourself (you have to hit for the heal to work), Light Green (Hunter) runes on buffing skills.
You can't choose which runes you get from the Rune Boxes in the store but I believe the most efficient are the R rarity boxes. They cost the most Sage Stones but this price removes a whole low-tier rarity worth of runes from the outcome table that you will never use. A very important rune is Rune of Guardian for Ultimate skill only. Upon using your ultimate, you get damage reduction up to 40% on SR for 12 seconds. I believe you can have two so two SRs will give 80% reduction.
You can find this option in blacksmith. There is no level requirement to wear gear so a level 1 can theoretically wear level 50 equipment, you probably won't have access to enough matierlas to level the equipment to 50 though. Use rarity B and C equipment as fodder and Ores of Enhancement to upgrade the equipment you're using. You can get these Ores of Enhancement as a random drop in Chasm of Abyss. Remember to be efficient with them and to not over-experience an equipment.
Gold / Rune Farming
The easiest way to farm gold in this game is to go into the multiplayer dungeon mode Chasm of Abyss (you can play solo if you want) and farm the first two dungeons unlocked after completing stages 1-1 through 1-9 with an S: Precursor of Disaster and Kingdom of Goblin.
Now, the best way to do this is to choose a Character that you definitely will not want to play ever, complete stages 1-1 through 1-9 with an S and DO NOT CONTINUE THE STORY FURTHER. When you select Random Raid Matching the benefit is you get Sage's Stone which allows you to buy runes in the store tab labeled "Sage's Stone". This store tab is important because you can obtain SR runes in the Grade R Rune Boxes (the most efficient I believe for SR runes). So, when you Random Raid Match with a Character who only unlocked the first two stages, you are guaranteed the only maps that drop the two most valuable sellable items for gold (25,000 each) Golden Crown and Golden Leaf AS WELL AS receiving Sage's Stones. Wait for people to join so they can carry you to make this process faster. Remember, do not go further in the story.
Gold and sage stones are shared between characters.
Easiest way to level is to go into Chasm of Abyss (multiplayer dungeon) click Random Raid and get carried. Do this until you are satisfied.
Gearing Up (End Game)
After you finish the story the real game begins: Chasm of Abyss grinding. Now, you can manually choose which dungeon you want to focus on but that completely depends on what options you're looking for on your gear. In order to get a better idea of where you should be specifically farming, you need to go to the Blacksmith and look over Carve Set Option and Merge.
In Carve Set Option, you can see where to find what materials by clicking the material image. Each Set has 5 options (no set bonus for 1 equipped): 2 will always be "grant a set skill" and increase set skill damage, 1 will always be some type of resistance stat (the 2 set bonus), and 2 will be actual stats like stat increase or effects like gain hp/mana on basic attack, movement speed, etc. Which Set Option you want will depend on which stats you want (particularly the actual stats gained and less so the resistance stat) and which Set Skill you want. I haven't tried all the Set Skills yet, only Frost and Arbiter, but each Set Skill is different in how it applies it's damage. Frost deals damage around you in an area of effect while Arbiter shoots down a diagonal beam summoned behind you aiming in front. There are others that affect the whole screen, etc. Best advice if you're new is to just get the Set Option that gives you stats that you want for now.
In Merge Option, you can see where to find what material by clicking the equipment image then clicking the material image. Keep in mind, merging materials into equipment automatically gives you the set bonus the equipment is associated with. For example, Night Xabel equipment will automatically have Vision of Ruthless Beast Set Option on it as soon as you merge it. Also keep in mind, you can change Set Options through Merge Set Option so you can change the Night Xabel Set Option in to Frost Set Option for example.