So when this idea of mine started to speedrun this game, I used Firewall. It got me time ranged around an hour and a half and what not. It definitely has some advantages over Ice Shards, however, after a friend who wishes to remain anonymous did test runs with it, it seemed the best way to go for the time being was Ice Shards. So the tactic for this route is using that.
Name and create your Thaumaturge and go into Casual difficulty. The drop chance increase on the higher difficulties do not outweigh the amount of health they receive. It also helps to have a character map around to reduce load times if you just started the game up.
Once you begin, skip the cutscene right away and you will hit the first load. Once that load finishes, skip immediately. You will need to do a lot of things at once. Open Katarina's page and make sure she is in Melee, set to Defend, 0% for HP Potion threshold, and have her pick up Gold, Health/Mana Potions, Essences, Magic, and Rare items. Next, disable Auto-Powerup then loot the corpse and chest behind you.
Continue running and attacking as you do. You want to trigger the explosion cutscene and pull as many of the enemies in with you as they instantly die and give EXP. Open the chest next to where you land and continue. As soon as you encounter the first Dreadwolf pack, use Ghostly Mirage and grab the chest by the fireplace on your right. Make sure to approach it from the northern side so you are less likely to get stuck. Continue running and killing so you can hit level 2 ASAP. You should hit it very shortly after.
For this level, and all levels the rest of the game, dump all ability points into Willpower on yourself. I will let this always be an assumption for the rest of the guide. As for skill points, do 2 points in Ice Shards, and 1 in Jagged Shards powerup. Go ahead and check items to see if you have any upgrades. You want to prioritize Spellpower first, cooldown second, and mana third. Anything that gives Ice damage is definitely better than something that doesn't, in the situation they both have the same Spellpower.
Change Katarina into Ghost form, and she will stay in this form for the rest of the run. Keep going and grab the damage shrine on your left. You want to grab a few groups of Dreadwolves before Ice Sharding them. Make your way to the Northern group of Outlaw Champions and kill them and grab the chest behind them. Make sure to use your powerups every time you can hit 3, especially for groups like these. You should level up now or shortly after. Put 1 point in Ice Shards.
Continue towards town and skip the dialogue and enter the town. Head towards the center of town and skip the cutscene. Go sell useless items and buy as many mana potions as you can. Turn the quest in and continue out of the town. Katarina should level up from this. From here on out, all ability points in Katarina go into Luck. Put a point in Incorporeal Defense. Talk to Grigori the Elder to take the Romany quest then head into the next area.
Head right to the group of Dreadknechts and kill them. Usually pulling them into a ball is fastest. You should level up again here or shortly after as you kill things while running, adding another point to Ice Shards. Head to the Romany camp and talk to Gaspar and choose option 1 (Help). Next head to the Nameless Wisp and choose option 2 (Begone), then option 3 (Lifespark). Identify the amulet and equip it. Continue to Snowpelt and kill it, then to the Werewolf Den killing things as you go ignoring the level up you got.
Once inside, level up Katarina and put a point in Spirit Guardian and Otherwordly Senses, and add Epic items to behaviors. Level up yourself as well and get Second Chance in Perks and one more point in Ice Shards. Then pull all the wolves and trigger the Vrikolak cutscene.
In the next part, you need to kill all the Summoner Sigils in one hit. Conserve your powerup to always have +3 available for them, and stand in front of them before Ice Sharding to guarantee a one-shot. You want to go counter-clockwise starting with the southernmost one. Then trigger the next cutscene and skip it and choose option 2. Open the chest next to the mayor then talk to him and teleport back to town.
Talk to the mayor to accept the quest, go sell all of your useless items, talk to Boris and buy as many mana potions as possible skipping both quests, then use the teleporter to go to the Romany camp and finish the quest. Then teleport back to town, talk to Doktor, and head to the next area.
While running to the bosses, you are going to level up a couple times, or possibly even once before entering this area. So I will go ahead and list the idea for leveling. You should hit level 8 before you reach the bosses. Make sure you have BIS for gear, 8 in Ice Shards, one point in Control and Ink Jump. For Tricks, you want Arcan Healing, and for Auras, you want 2 points in Frost Adept and have it and Rampage as active.
Skip the cutscene and go for Monsieur Flambeur first. You want to kill him before he goes invincible if he does you need to wait it out. Nest you go for Judge Obesovsky, then Electrigerous Beast-King. You will use Control on Vrikolak Predator as his healing is too strong, and it bugs the quest to count as if he died. While he is Controlled, use Sluggish Time, trigger the cutscene, skip it, and teleport to the Mines.
When you get there, you will want to set up. Get Second Chance in perks, make sure Katarina is good to go with now 3 points in Otherworldy Senses. Make sure gear is BIS and continue to the next boss room. By the time you get to the boss, you want to try to be level 10. You want to get Inventive for perks, 10 in Ice Shards and 1 point in Elemental Damage, 1 in Painless for tricks, 1 in Quick Response for Auras, and 4 total in Frost Adapt and set them both to active auras. By this point, you will put all remaining Skill Points for Katarina in Arcane Awakening. You might also be able to get another perk, if so, Elementalist is next.
Skip the cutscene and turn on the Chargers, I usually go clockwise. Then when you hit the switch, run to the Drillworms face and Sluggish Time, and +3 powerup Ice Shards him as much as you can. You should get it in one cycle, if not judge how low it is, and you might need to do another cycle.
If you have not already, get Elementalist perk and equip Ghastly Shape. Load the next area after making sure gear is BIS, and start running. After the first set of stairs to your right, Ink Jump forward to skip a cutscene trigger. Run to the Secret Lair. For the first part, you want to somewhat ignore most things since now you have a lot of running skills and survivability. However, if you can do kill a couple of groups as you want to level up after you get to the lair.
Get one more point in Elemental Damage, and put 1 point in Blindness and one more in Painless. Sell all pointless items and continue to the Main Square. Kill all enemies and skip the cutscene. Head to the farthest away Electric Coil, then go up top to get the next. Make sure to break all boxes near the Coil to get Machine Parts. Next, teleport back to the lair and then right back to the Main Square. Get the southernmost Coil first then go up top to get the last one as well as the chest along with it. Teleport back to the lair.
Do the quest objectives, make sure Katarina is good to go, check BIS gear, stock up on health and mana potions, and continue.
(Will continue being worked on)
