Best place to farm high rarity decorations?

[Ahriman]

I wanna get better decorations, I hit MR100 finally so I can do almost everything now I think. Is there a good quest to farm decorations fast by myself?

[Crystal]

Tempered Teostra and Tempered Furious Rajang event quest.

Any tempered elder event, especially those that takes place in Seliana Supply Cache.

[Lars]

"day of ruin" event quest for rarity 12 decos, "mew are number one" event for rarity 11 decos, and any threat 3 tempered investigation with 5 purple boxes

[CookedMeat]

Day of ruin is easiest out of three tempered elder jewel quest. Utilize dragonazor and binding barista shot can make the fight easier.
Mew are number one can be difficult to deal with, depending on your skill. But the jewel it offers is less than day of ruins.

[Ahriman]

Ok thank you, I will give Day of Ruin a try, think I'll avoid the tempered furious rajang.. lol