How thorns (dual blader) works

Naw, it just means they suck at coding. It *should* have been made to work at full power on all Dual Bladers, not just the one that casted it. But they totally forgot about it and made it work at half-power on everyone who receives the buff. And in your example, they'd just all go partyless anyway.

Going party is more exp though. Hmmmm with the newer class info in extraction section, this dual blader might come to GMS very soon.