I might have logged in last in 2016? Anyway I have a T6 battler with the following set:

Iron Fireside Lantern Frost Quill Reborn Icewand of Doom Shards of Space and Time Ice Rose Phoenix Quill Shinwas Temple Shard Recycle Blaster

I'm not looking to fully redo my build, but I guess just have goals for the current meta, whatever that might be. E.g. What should I try to buy in the Battle Shop? What should I be focusing on to move forward?

Looks like a pretty good set!

Maybe you can replace the Frost Quill with a once per battle 100% freezer. There's the in the battle shop, which is pretty budget but does just fine. There's the which is a tiny bit better, but also a whole lot more expensive. I'm not sure it's worth it at these prices. You might be better off waiting for tier 8 to get a for a tenth of the price of the DDS. are nice to save up for. It can be used in combination with the Recycle Blaster to blast an extra weapon. That can be the difference between win or lose for the tougher opponents. You can also save up for in case you need two once per battle healers. Though it's quite expensive, so I wouldn't put a lot of priority on it now, your Phoenix Quill will do just fine. It's nice to have for boss battles, where it might give you an extra turn before you have to heal up again, or for some of the tougher opponents when you can't quite block enough damage to outheal them.

What scrolls are you using? What opponent are you trying to beat?

I have to admit that I haven't paid attention to some of the more recent weapon additions, so I might be missing a few options. At tier 6, the Reborn Icewand of Doom is still one of the very best options, can't really go wrong there. Maybe you could replace the Shards of Space and Time with which does a bit more damage and has a low chance to freeze. And maybe get a because it's so cheap, just in case you need a weapon with extra heals on it.