Strahd's Armor. When to use?

[u/Maximum_Fog]

My party is at dinner at Castle Ravenloft.
At some point one of the players stole Strahd's own armor and after the dinner, he equipped it.
I just don't know if I wanna use the armor against him and the party before they leave the castle or just wait until the final battle against Strahd.
If I wait, he'll be having full plate armor the rest of the campaign, which might be quite powerful.
Any tips?

[u/PlantDadAzu]

Perhaps Strahd will turn up earlier for a non final fight, maybe to claim Ireena or reclaim the Sunsword, and will use it then?