@Loop_Stratos - It's actually pretty simple to do the HC quest as long as you use the following strategy:
1) Every single level up, every any skill crystal, put your bonus point in DEFENSE. With high defense enemies for the bulk of the game will do no damage to you. This allows you to sustain through most of the game
2) Your first level use 3 skill points to get HEAL. Do not EVER USE ANY OTHER SKILL. Offensive spells barely do as much damage as normal attacks, and mana doesn't regenerate without items. Never use MP in anything other than healing or crafting, its simply not worth it
3) After getting Heal, use all points on the combat path (right side). Move along the path prioritizing getting to the +5 Defense nodes first, then go back and get the +5 attacks, then just fill out the entire path. After that go to the left path and prioritize Potion Duration. This lets you mix up health/mana regen potions that last for a long time, very useful for later levels (but less useful than combat stats in early levels)
4) As you go along down levels, absolutely prioritize putting health and mana regen on items. The goal is to get yourself into a sustain build where enemies do so little damage to you that you actually HEAL when killing them. Usually there will be 2-3 types of enemies you can heal off and 1-2 that will hurt you. So you kill an enemy that hurts you, then go and kill 1-2 that heal you to get back to full health/mana. This allows you to clear the entire level and remain at full health
5) DO NOT USE POTIONS UNLESS YOU ARE GOING TO DIE. With a sustain build you shouldn't need potions. But every shop you get to, if you have extra money, buy potions and stockpile them. You will need them for the last few levels and the boss.
6) DO NOT USE MAGIC PICKAXES. Save them. They will be used in the final levels. If you have extra money, have bought all potions and useful crafting materials in a shop, go ahead and buy pickaxes.
7) For about the first 55 levels, CLEAR EVERY LEVEL. Every enemy, every time, XP means more stats and skill points to keep your sustain ahead of their damage. Every crystal you get further increases your survivability, always be on the lookout for secret rooms and item upgrades. Don't just mindlessly attack every enemy, though. With a proper sustain build, exploit the enemies that do zero damage to you to heal yourself, and then kill enemies that can actually hurt you. Alternate properly between hurt/no hurt enemies and you should be at 100% health/mana easily for the first 50-55 levels.
Once you have potion duration you can start crafting some defensive/regen potions if you're having a little trouble with enemies on these levels, but stay away from using healing/mana potions, you want to stockpile those.
8) At about level 55 or so you start encountering a lot of enemies that simply do too much magical damage to sustain through (the wizard types). Avoid them if you don't need to kill them for an item, heal up on the titans and pure attack guys (if you stacked your defense like I told you they should do no damage to you). Continue to explore every level to the max, though, but no need to fight wizards for gold/nothing. Go for all the crystals and items and of course secret rooms, but now you'll start leaving dangerous enemies alive.
At about 60-65 start crafting a battle set with bleed for the final boss (bleed is better than attack because you can get it in higher numbers). Your final boss set should have no mana/health regen on it at all, because it's not useful in combat.
9) At about 70 or so you simply can't sustain 100% anymore no matter how much you stacked defenses. There are simply too many magical enemies of different types and too few physical enemies. If you built some good magic defenses you can still kill some of them to keep your health/mana high, but at this point you want to just go straight for the stairs every time. This is where you start using the pickaxes - to avoid highly dangerous enemies (the dragons and high powered wizards), to get to secret rooms or useful crystals. But now your priority is just to finish the game, so go for the stairs. Especially the last few levels you'll need to fight almost no enemies and just go for the stairs with pickaxes.
10) When you get to the final boss, first he summons a couple normal monsters to kill, kill them with sustain. Then when you fight the boss switch to your battle set, make sure all of your potions are on your bar, and fight him. He has a huge number of HP, so you'll need a large number of potions (probably 30-40 depending on your gear and what type they are), but as long as you stockpiled them he should fall pretty easily. When I did it I killed him with 50 potions to spare.
11) That's it! Luck is not a huge factor as long as you follow this strategy. I did it 3 times in a row (once here, once on Kongregate, another time just for kicks) not coming close to dying at any point. As long as you get that sustain build going and save your pickaxes, luck is just not a big factor.
Hope that helps!