It does nothing to Canadia. I could see it potentially being useful in, say, tag events where Yugi uses Swords of Revealing Light or something. In PvP, it's unlikely to be especially useful, though. I guess you could use it to potentially counter cards like Shadow-Imprisoning Mirror or DNA Surgery temporarily, though.
I activate fiendish chain, now your monster cannot attack and activate it's effect
Kaiba: Not so fast, i screw the rules i have money, now your fiendish chain is nullified.
Kaiba: Because i have money.