This build focuses on magic exclusively. If you want to be a pure magic user, there really is no better option than using hexes. They have fantastic scalability with their main weapons, and great versatility in their use. You're able to deal with any tactics thrown at you with a wide variety of attacks and counter strategies. This build is great for both PvE and PvP, simply by changing out your spell selection (though, to be fair, it is better optimized for PvE).
This is the build for you if you're good at thinking on your feet and like having a large toolbox of tactics to use. If you want to just spam one uber-powerful spell, this is not what you are looking for. That said, this kit will give the ability to overcome any obstacle or opponent if played smart.
Dark Sunset Staff +5
Dark Chime of Want +5 (short range)
Lightning Dragon Chime +5 (long range)
Hexer's Hood +5
Hever's Gloves +5
Velstadt's Armor +5
Velstadt's Legs +5
Third Dragon Ring
Chloranthy Ring +2
Clear Bluestone Ring +2
Southern Ritual Band +2
Great Lightning Spear x2 (PvE) -or- Sun Spear (PvP)
Dark Orb x2 (PvE) -or- Resonant Soul (PvP)
Scraps of Life
Soul Greatsword (If you have the slots, depends on whether you got the +2 southern ritual band)
PvE tactics for this build are fairly straightforward. Utilize your bottomless pit of dark orbs to ruin everything in front of you. With these stats and this equipment, each orb will do in the ballpark of 500-800 damage depending on the enemy, and you'll be capable of casting one every 1.5 seconds. You have plenty of other tactics to use, like using scraps of life to maintain separation on a horde of enemies, or using your other bottomless pit of lightning spears to snipe enemies from a safe distance. Dark Fog is also very very useful in certain situations, mainly against stationary targets like enemy mages or shield using slow opponents. For example, poisoning a Syan Knight will kill it outright, just wait a minute. Dark storm is fairly situational in PvE, and is best used in coop. This spell is also the reason you want to be wearing heavy armor, because you are nearly guaranteed to take hits while using it, but the damage an enemy will take while attacking you is almost always worth the trade (it generally kills things outright).
PvP requires an extension of the PvE tactics above, but you must be much more savvy in your casting, and faster. Success is rarely instantaneous (no crazy one shot backstabs in this class), but you can almost always impose your will and win a protracted battle. Using spells in combination is key, and you must always keep the pressure on. If you're facing a heavy melee opponent, using scraps of life to maintain separation is extremely important. If you manage to score a hit (which will knock them down) follow up immediately with dark fogs to inflict poison. Or, if you're facing a fast melee opponent, bait them in with dark storm, and follow immediately with a soul greatsword if they are smart enough to not rush into the storm. If the fight is long range against a mage or archer, Dark fog followed by sun spears usually wins the fight quickly. You may want to substitute the Sun spears for Crystal Soul Spear, as that seems to land hit more often in PvP.
I'll post a leveling guide for this build if you'd like one. But, there really is no avoiding the fact that leveling a sorcerer can be a real painful experience. The Bastille in particular will make you want to cry.