What are you upgrading the sealed sword to?
What are you planning to run?

For instance, Faust is awesome in the jelly palace. If you're upgrading to Faust and plan to do jelly a bunch, sealed first.

As a general response, upgrade your general use weapon first and then work on specialty items... so as a general answer, calibur.

Batabii seems like an excitable fellow. Final Flourish is just as good as Barbarous Thorn Blade, although its charge attack is a little harder to master. So there's no reason to give up on that Swift Flourish.

I would probably upgrade the Sealed Sword to Avenger first. Then I would get a Nightblade (I prefer Acheron to Gran Faust), then upgrade the Swift Flourish and Nightblade in any order. Leviathan is a nice sword, even with its normal damage, but I rarely use mine, because I have specialized swords, so I'd ignore the Calibur for a good long while.

When i started playing this game i was going for seal sword 1st.
It was like my dream to get seal sword lines.
But as an experience player, i suggest you go for the swift flourish line.
Then get Polaris gun, then you will be set for "EVERYTHING" .
It took a while to figure this out. The best combination for 2 weapon slots.

Well thx Bopp and yes I'm not crazy lol

If you enjoy Pvp more then you should work on the sealed sword lines and/or the flourish. However, if you are interested in making money with these swords here's a run down of my own useless statistics and thoughts.

Levi-

From my experience, the most cost effective and economical approach is the Leviathan. Its reliability allows you to take it anywhere in any depth safely (i often bring my levi to FSC). Its also great to get as you grind up more money and heat for your other swords. Unfortunately as a PVP weapon its fairly useless. (It's cost effective because you don't really need other swords once you have the levi and that saves up ALOT)

Flexibility: 10/10
Money/heat making: 8/10
PVP: 2/10

Pros: you can take it anywhere in the clockworks and smack everything!
Cons: Tickles people in PVP

DA-

Makes FSC (and most arena's) alot easier to handle which means lots of heat and lots of money. That last room of in arena's with mecha knights? With one charge attack you sweep them across the room.

It's also fairly decent in PVP. So a great weapon for end game players (people who run FSC and PVP alot). It isn't as flexible as the Levi in handling all situations but most enemy encounters are neutral or weak to elemental so its a close 2nd.

Flexibility: 7/10
Money/heat making: 10/10
PVP: 8/10

Pros: Does great damage in FSC which is usually what the end game of Spiral Knights come to. Great for arena's and decent in PVP.
Cons: Not the most flexible sword

GF-

The Gran faust shines in the Royal Jelly palace and in PVP. Elsewhere, its just shiny unless you face slime and gremlins. Most level's feature slime but they are so easy to kill (for me at least) that you really don't need to carry a GF to face them. Gremlin's on the other hand are quick and agile which might make the GF a little hard to use starting out. But given enough practice a GF can be deadly against them. The thing is level's with gremlins don't have alot of heat/crowns which make the GF limited to the Royal Jelly palace in terms of earning the mula (as of the date of this post).

Flexibility: 3/10
Money/heat making: 6/10 (an extra 2 point goes here if you are intent on Royal Jelly Runs)
PVP: 9/10

Pros: Using this sword in PVP is greatly satisfying. Can destroy jellies.
Cons: Not flexible beyond the pros.

Barb Thorn/ Final Flourish-

These pure piercing swords do a surprising amount of damage on things they aren't made to fight against (undead/gremlins) and are deathly to fiends and beast. They are also the current favorites in pvp for their fast attack speed and brutal damage. They are slightly less flexible then the DA in terms of earning money due to fiends and beast not having very profitable levels (as of the date of this post). But its ability to handle the majority of just diving into the clockworks is decent but due to the lack of profitable beast and fiend levels its not a great money making sword (as of yet).

Flexibility: 5/10
Money/heat making: 6/10
PVP: 10/10

Pros: Efficient/professional weapon in PVP.
Cons: Mediocre at making money.

Arctic-Fern, can you explain why you think shadow drops off in utility in Tier 3? I'm honestly asking.

With Acheron, I do gobs of charge attacks on Tier 3 gremlins (e.g. in deconstruction zones, and gremlin healers everywhere), and I'm glad to have it.

I'd say make an Avenger.

Its great for Firestorm Citadel, Ironclaw Munitions Factory, pretty much any arena, graveyards, and its a decent weapon to bring to Jelly Palace.
I can't say about Caliburs as I've never made one. Supposedly its great for swatting Vanaduke's mask, but I haven't gotten round to making a sword just for one floor. As for Flourishes, there usually aren't an awful lot of things to prick, unless you're going to Gloaming Wildwoods or something. I'm not saying its useless (it is to me, compared to a snarble barb), but its not quite as handy as an Avenger. Certainly Avengers would be a higher priority to me.

Xaechireon says, "As for Flourishes, there usually aren't an awful lot of things to prick, unless you're going to Gloaming Wildwoods or something. I'm not saying its useless (it is to me, compared to a snarble barb)..."

A piercing sword is extremely useful, because it destroys fiends and beasts, which are two of the most troublesome monster types in the game. I don't see how you think that a Snarble Barb is more useful; it's nearly identical to a flourish.

Before Lockdown arrived, a lot of people ignored the piercing swords, and a lot of people complained about fiends and beasts. Now that Lockdown is here, people recognize the value of piercing swords in Lockdown, but many of them haven't yet figured out how awesome they are in PvE.

There is no JK, I"m pretty sure you mean RJ, and RSS makes that battle so much easier.

I like the fair, unbiased comments I have seen here, but if I were to provide my advice...

Which sword do you enjoy using the most?

Which sword do you find yourself most proficient at using?

Would you prefer a fast/weak, average, or slow/strong sword?

The chances are that the answer to these three questions will lead you to the answer you seek.

For me, I enjoy my levi and my v striker, and I dont enjoy my troika.

I am most proficient at using med/fast swords

And I prefer a med/fast weapon to a slower one.

And look, the answer to which weapons I should have: Calibur line and Cutter line, and possibly brandish/florish.

It takes time to find which sword suits you best, but once you find it, you will instantly be better off for knowing.

Incidentally, should anyone wish to know what type of weapon suits them best (speed, damage, status), just ask me and I'll ask you a few questions, and then I should be able to tell you which is best. (I say this because I know quite a few people who just get a popular weapon (I'm looking at you, DA/GF) and do terribly, simply because someone else said 'its the best sword in the game'. I want to let these people know that the best sword for them is not necessarily the best sword for others.)