Dren's player had built a classic "thief", very specialized on breaking into places and stealing the treasures within. With a high dexterity, he will be skilled at most thief related checked, while also being very accurate should he need to attack. His low toughness, however, makes him both more likely to be wounded if hit and more likely to die if wounded.
Dren wears a full suit of leather armor to try and compensate for this, bringing his WAC (before wounds) up to 10. While there's nothing stopping him from using a shield in melee (particularly the buckler, which lacks any penalty) along with his shortsword, Dren doesn't want to have to worry about dropping it in case he needs to climb a rope or pull out his crossbow in a hurry.
Dren's high Wisdom score will come in handy on skill checks related to knowledge and observation. It would also be handy for some arcane spellcasting, but Dren doesn't know any energy types.
Dren is not a disciplined individual, but he is passsionate, resulting in him having a slightly above average ability to stay in the fight when injured, even if he's most likely to use that ability to run away faster. Interestingly, Dren's passion and loyalty would make him a decently faithful man, if he could ever have been bothered to spend some time praying. With more wisdom or discipline, Dren's player might have chosen to select a prayer as one of his educations. Healing light would be a nice choice, given how squishy the lad is.
Dren starts our story equipped with a short sword and a crossbow. Note that the numbers written here are the weapon's bonuses to hit and wound, not the totals. In a fight ability scores can change fast, and it's often easier to write down the numbers you will add up and do the addition in your head, than to write the totals and erase half the character sheet when you resolve wounds.
Dren's Discipline and Wisdom entitle him to 11 educations, which unsuprisingly are being mostly put into skills, and mostly skills a thief might use. 2 are spent on languages, while 3 are put into likely weapons he might have to use. Dren never had the patience for the magical arts, but the character is under no game rule obligation to keep away from magic.