First thing - my scroll game is weak, and I know it. I really need advice here. Second, need to work towards having a useful array of weapons to beat some of these harder opponents. My basic set generally consists of this right now.

Here are all the random weapons that have found their way into my armory over the years.
SPOILER (click to toggle)

I do have another pet I'm training up, who's T4 right now, but if there's things in there that can just be gotten rid of, that would be great advice too.
Now, scrolls.
I only have
See, weak.
My pets current stats
Level: 654 Health: 1600 / 1602 Strength: 1600 Defense: 1600 Speed: 1600 Intelligence: 948
So, yeah. What can go, what can stay, what's useful to have against some specialized opponents etc. All the advice please.
I would definitely pick up the aftershocks scroll as your main infinite use scroll. Picking up more cobalts and sancturia exodin wouldn't be bad either. Freezing scrolls like psycho smasher and shriek of despair are very good. Gift of the forj has been really handy for me if an opponent steals your healing items or you need the extra heal.
As for weapons, definitely replace the harp with the energized helmet you can make in the battle shop as your default freezer. Ornate hook swords are very nice and you can buy them in the mc. Unstable syringe is also a great weapon you could buy outright or wait until you can win your own. Overall your set is in good shape and it's good that you have a variety of weapons to choose from depending on your opponent.
Congrats on T10 btw!