Most runs I've seen get the Jevilstail. But isn't the Devilsknife a better option for a full game run? It does over 400 damage to King with a Red Buster, and it's more powerful than the tail. Once you get to Chapter 2, the knife speeds up so many fights. And getting the knife (and using it on e.g. King) doesn't ruin a pacifist run.

The only advantage I can see of getting the tail instead is that it can be taken off Susie and put on Kris or Ralsei instead, if that's ever necessary (it maybe slightly speeds up Giga Queen but in my casual playthrough I used Frayed Bowtie and Iron Shackle on Kris to boost his damage for Giga Queen; as far as the whole game goes I think the time saved by having the Devilsknife would be well worth it).

What do you think? Are there more reasons to get the tail instead of the knife?

The Devilsknife takes around a minute longer to obtain because of the attack animations in the Jevil fight. Even ignoring that, in the King fight you can't kill him in less turns unless you use Rude Buster strategies, that are very difficult without even saving that much time because of attack animations again.

It doesn't stop there, in Chapter 2 you get the Auto Axe which gives 4 AT. This is only 1 lower than the Devilsknife, making it so having the Jevilstail that gives 2 AT actually grants you higher total AT. Even factoring in that you have 2 more magic with the Devilsknife, each point of magic grants 5 damage on Rude Buster and 6 damage on Red Buster while each point of AT grants 11 per Rude and 13 per Red. Getting the Jevilstail also allows you to 3 Turn Berdly 2 by putting the Jevilstail on Noelle, and you can 1 turn the Maus fight by putting the Jevilstail on Ralsei.

Essentially the Devilsknife deals less damage, takes longer to get, loses time to multiple Jevilstail strategies, loses 1 AT on the Giga Queen fight, and there aren't any fights where the 10% TP decrease speeds up the fight dramatically.

I see. Thanks for the detailed explanation!

I don't know if this matters but I was able to kill King in 8 turns even while missing a few crits, with the Devilsknife. That's a whole 2 turns quicker than Shayy's 10 turns in his world record run.

EDIT: I did the calculations.

Turn 1: Susie Talk, Attack, 75 damage Turn 2: Attack all, 315 damage Turn 3: Red Buster, Attack, 485 damage Turn 4: Red Buster, Attack, 485 damage Turn 5: Attack all, 315 damage Turn 6: Red Buster, Attack, 485 damage Turn 7: Attack, Rude Buster, Attack, 440 damage Turn 8: Do what you want, 200 health remaining if you hit all crits

So you can miss many crits and still get an 8 turn kill with the Devilsknife. (Or defend with Ralsei once or twice, giving enough TP for an extra Red Buster.)

In an all bosses Chapter 1 run, this may be quicker than getting the Jevilstail and doing 10 turns. But in a full game run, probably not.

EDIT 2: I just recalculated it and realised a 7-turn kill is possible with good grazing. Attack all turn 1, then Defend with Kris and keep Attacking and using Rude Buster, dead! That's 315 + 350 + 5x440 = 2865 damage (65 leeway for missing crits). Tested and confirmed.

Devilsknife loses so much time to get in Chapter 1 (45 seconds to 1 minute) and comparing to Jevilstail, it would only save about 10-20 seconds in king and it becomes worse than Jevilstail in CH2, it’s just not worth it right now.

Okay, what about now? Obviously it's irrelevant for the Titan because there's absolutely no way I'm grazing back up to 40 on the first turn of Unleash, but for the Knight, as far as I can tell Devilsknife-Dealmaker-FrayedBowtie deals more or less equivalent damage to ToxicAxe-Jevilstail-Dealmaker, while the reduced buster cost allows Ralsei to get hits in instead of defending all the time without losing busterspam pressure.

The knife could be useful for the knight and the titan especially since it only costs 40 to to use rude buster. I think runners are still getting the jevils tail because it has some sort of money-making ability I think, but in theory devils knife could be faster

if youre doing rude busters on titan something has gone very wrong

No, but they’re really useful for the knight

At most, with the knight, this would save maybe a turn or 2, and most attack turns are ~10-15 seconds for most enemy encounters. And Susie gets a far better weapon in Chapter 4 when doing all bosses anyways.

I can see a valid "safe route" option to go for it if you specifically have trouble grazing the Knight's attacks, especially with the Pink Ribbon's nerf, but there's a 0% chance it's actually faster.

Also no, people go for jevilstail because it has far more benefits outside of the knight and killing jevil is much slower than pacifying. It's dealmaker that increases money-making, and unlike Jevilstail, there is a valid alternate route that kills NEO and gets the Puppetscarf because they're not too far off length wise and the Puppetscarf is actually a pretty good weapon.

It’s honestly too bad the knife has 0 benefits in that case

Rude Buster on Titan is basically impossible unless you have Tension but or something, because 80 for unleash doesn’t give you much room to fit in a Rude Buster. My main method on most boss fights is defend on the first turn unless Kris has a good act or Susie has a good magic that will last a while, then use Kris and Ralsei to defend with Susie using Rude Buster, however said strategy would be highly unbeneficial if used on the Titan or Jackenstein because of reduced TP.