Sprites are pretty good aside from the ring, katana is a bit eh but it’s not the worst.
It feels like you definitely just focused on the sprites here though. None of these items compare to any decent tiered equivalent, and there’s no uniqueness to the ability or weapon.
A triple shot star sounds cool until you realise that you will literally miss 2 of the 3 shots unless you sit on top of an enemy, and those types of weapons hardly come into use, and this is meant to be part of a set. Plus, it does too low damage to be useful compared to even the t4 star. Also, there’s no MP cost, no arc gap, no fame bonus, no feed power. You get the idea.
The katana is just bad, unfortunately. I assume it still hits multiple enemies since you didn’t specify but it does less damage and has less range than tiered, and frankly it’s literally a worse Masamune with a weird shot pattern. Which again, we aren’t even told what the pattern is since there’s no amplitude or frequency, plus the other things that should be here, like for the star.
The armour is the only okay item here, but that’s not by much. Sacrificing 2 def, 1 dex, 7 vitality for 5 speed seems alright but then again the Leaf Dragon Hide does the same gimmick but arguably better. Also, the ring LITERALLY COUNTERACTS THESE STATS, which is a big no no when making items meant to work in a set.
The ring follows the trend of ST rings being utter trash, so I guess that’s ok.
Here’s a tip or two;
Make sure you know what you want from your set. These just sound like separate items put together into a set, but nothing really works together, the armour doesn’t complement the ability or weapon, the set bonuses also don’t work with anything. Choose some aspect of the class that you want to make even better, or fix. Or, make a neat ability idea and then work to make a set that amplifies its benefits or make up for its drawbacks.
Make sure you CHECK existing items, especially tiered, before you decide on stats. Whenever anyone looks at how your items would work in the game, they’ll compare it to existing items, so do it before they do.
I don’t blame you for not having great descriptions/names, as not everyone is a great storyteller. You can ask around to see if anyone can help you out with that. iirc @Seelpit does good in this department usually.
Good sprites, not so great stats, don’t take everything I say too seriously as I seem to come across as really critical sometimes 
