Going at this completely free to play here:
Skolver Coat
Skolver Cap
Barbarous Thorn Shield
Barbarous Thorn Blade
Argent Peacemaker
Also Blitz Needle (although, keep in mind I only have 2 weapon slots)
So right now I'm at the 3* level with all of these and I just want to make sure it makes sense to continue before investing crowns in it.
For a two-slot hybrid sworder/gunner, a piercing sword with an elemental gun is probably the best combination. The elemental gun is fine (although of course not great) against slimes. The piercing sword is actually pretty effective against gremlins, due to its speed and size, even though its damage is neutral. So your weapons are good.
Your armor is awesome for sword damage, of course, but doesn't offer great defense. Consider getting one piece of Vog Cub next. Just one piece helps a lot in FSC.
My general advice for people like you is here.
My information might well be of use to you knight. I've always got something interesting for people like you.
Makes perfect sense.
You may also wish to invest in Vog Cub (and an Acheron on the side, potentially), if you've got time/cash - I take it from your Blitz that you'll be doing Vanaduke runs eventually. If you're working for an Argent Peacemaker, you may wish to get the Nightblade before upgrading the Snarble Barb, since this will make your life much easier in RJP (assuming you're not purchasing an Antigua off the AH directly).
You might also want to get an elemental sword eventually as well, but you've got the damage covered with the AP so it won't be exceptionally urgent to get. It will help in dealing with hordes of zombies, though, given you only have two weapon slots and in FSC one of those will probably be taken up by a Blitz. (Double piercing isn't ideal, it makes dealing with Oilers, Blast Cubes and Red Rovers really irritating.) Unless you're going AP/Blitz in FSC, in which case it'll still take a fairly long time and your index finger will be sore.
He already has the 3-star versions of all, and hence he already has Antigua. This makes Acheron unimportant again. I mean, I love Acheron, but BTB is more important.
I do wonder what his FSC loadout will be. Defensively, I guess it will be BTS, Skolver, and either Skolver or Vog Cub. Offensively, it will be Blitz Needle and Argent? Or Blitz and BTB? Blitz and an elemental sword might be better, as Aureate suggests.
...derp.
Thanks for pointing that out.
Pretty standard swordy set; works nicely. Only time you'll have a problem is against slimes and gremlins, but your AP should help take care of them enough. Start thinking about investing in more weapon/trinky slots, though. They don't cost much and will open up options vastly.