30% uptime nature's grace
50% starsurge procs used
50% uptime moonfire/sunfire on Horridon
used 4 nature's vigil on a possibility of 6-7
you did not use any pots.
Horridon for a balance druid is pretty easy, use your eclipsed dot on all adds, keep double dots on horridon and spam your starsurge procs.
Dont bother hard casting on adds, not worth it, just spam string dot, weak dot if you dont have any SS proc, rinse and repeat