Stone/Thunder is actually Blu's go-to spell for magic damage, /Sch, Set magic Attack, wear all Hagondes, Dual Wield Anahera Saber + Tamaxchi, and spam Stone1 for 1k damage just like the Blms.

Charged Whisker is alright, but, not worth the cast time compared to Stone/Thunder.

You're better off meleeing though unless you need the magic damage.
If you need the range but physical damage is better spam Glutinous Dart and use a Str/Blu Skill/Acc setup.