When Strahd does get furious, I plan on having him use his Children of the Night and lair minions (wolves, bats, rats, specters, shadows) to disarm the party of these items and abscond with them before he even bothers to deign to fight them.
You know what would be fun? Have someone let the PCs know in advance that Strahd is going to try to steal their stuff. There's three ways that can go:
(1) PCs fail to thwart the theft and get crushed in their next confrontation with Strahd (unless they find a way to generate some other advantage).
(2) PCs thwart the theft, Strahd either tries again or just brings enough firepower to the party to win anyway.
(3) PCs manage to trick Strahd into thinking the theft has succeeded (Nystul's Magic Aura?), Strahd attacks them at his leisure, PCs go "Aha!" and whip out the sunsword/etc. anyway to his surprise and dismay, and then the PCs crush Strahd.