The basic idea is to pump as much as you can into VIT and END, and some in Attunement as well to equip some spells. Use weapons that aren't based on stats for damage, especially Chaos upgrade path once you get access to it which increased damage based on humanity. Keep you humanity up and you will be a wrecking machine that is very durable. This could also double as a VIT build, and you would probably put slightly less in attunement and pump extra in VIT.
I don't see how you would need any more than 16 STR and 12 Dex for this build, so I'm not putting another point in those.
Is there an item that you need to cast pyromancy spells? Also, where do you learn spells.? Thanks for the build info. Also, itsn't it hard to maintain high humanity? If you die, do you just lose it all?
You need a Pyromancer Flame to use the spells. You can get one by saving an NPC in The Depths. He'll be trapped inside a pot, make sure you roll into the pot and DO NOT attack it. This same NPC will also sell you a few basic spells.
Accumulated Humanity is dropped where you died, just like Souls. --- Now you see! Mazinger Z's power!
And you can farm humanity later, so its no big deal if you lose some, you could easily get 20 or so in just a few minutes. And with a Chaos +5 halberd or claymore, you will be doing great melee damage too.
Combustion also comes out really fast and can beat melee attacks on most weapons, and if they don't have any poise on their armor it will interrupt them. And I would be glad to trade a combustion for a melee hit with them.
I haven't gotten fire storm yet, but I know in Demon's Soul's you couldn't block it with a shield. Isn't that gonna be great when some noob runs up thinking hes gonna interrupt my firestorm, just to get BBQ'd.