Tactics: Pull the Hydras directly outside of Ember Light Camp to avoid the Flesh Golems and Phantoms as they pull seperately. Beware a lone pop-up Phantom along the water's edge to the right just outside the outpost.
Suggested Solo #3: 55 Invincimonk with Fleeting Stability, Dwarven Stability, or "I Am Unstoppable!". Avoid the Phantoms since they have two interrupts as well as Drain Enchantment. Both Ray and Shield of Judgment work, but SoJ is more effective. (Alternately you could bring a set of high armor/high health with a smite staff/wand and pull/kill phantoms independently prior to engaging the Hydra's with your 55 build. The phantoms only hit for ~10dmg and you should easily be able to wand them to death, removing their ability to interfere with your run)(Sand_Shards is a nice spell to have up prior to engaging Phantoms as their enchant removal will trigger the earth dmg AOE speeding up the process)
Suggested Solo #4:N/Mo SS. Bring SS, You Move Like a Dwarf, Balanced Stance and regular 55 survival skills. Using SS on the Phantom while it is knocked down from YMLD lets you kill it easily in alternate gear (just be sure to use SS first and then YMLaD during the cast, otherwise aftercast delay gets you) and you're free to kill the Hydras.