the build mainly revolves around pyromancy at first alongside the attunement slot; then gradually move onto strength and dexterity. you will have that extra speed in casting time until your next play through. the 15 intelligence will be the last thing to work towards. trust me it will be well worth it. with a diverse build to play with any type of weapon or your choice. enjoy if you will :)
P.s when your playing through the first time and you evenly distributed your points across the board your character will scale best with quality graded weapons. (C rating)