Salire (sweetheart) is an Ice magic damage dealer. High MAG from passives, and 25 spirit penetration from her master ability. Lacks offensive buffs without her EX, but she has some elementless magic attacks from her sub-jobs to deal with ice-resistant enemies. Otherwise, you can play her as a Time Mage support to spam Haste for your team.
She has an Energist job, making her somewhat similar to Garvall. Decent range, no cast time, and excels at short fights, but high cost for some of her skills. This might not be a huge issue since she has 195 AP, making her the highest out of all the currently available units. AGI-wise, she's a little lacking compared to newer and relevant units, but she can be surprisingly mobile because of Pulse and/or her time mage abilities. Her limit burst is an amazing ability that can potentially turn the tides around in PvP. It deals damage and dispells the enemy's buffs and increases her CT, allowing her to get another turn faster.
Her EX abilities are surprisingly lackluster. The 2 ability upgrades only slightly help her damage dealing part, but the job level 25 ability gives her a good offensive ability that can deal damage and increase MAG at the same time, which is the only move that gives her a damage buff in battle.