Addis is the backbone of this Freeze-resistant team, sporting higher DPS than Aeleen and better multi-target damage. He'll often waste his upgraded Bamboo Cutter on smaller enemies, but when Poison or Bleeding does land on the boss, it's a nice bonus. Valiant Crown is suggested for synergy with Lowen and Aeleen-- between the two of them, Addis will enjoy constantly boosted Defense and Strength.
While Aeleen is usable as a lead, her support-oriented kit naturally lends her in the second slot. Her main function is to buff and support Addis while also keeping the healers alive. A Valiant Crown can be used for extra damage with Valkyrie Blast, her low-cost AoE Skill.
As Myriage Lake is one of the more difficult IO stages, having two healers certainly helps. Lowen is a great option thanks to his powerful burst heal and Defense buff. When paired with Wedding Xania, Lowen's lack of Freeze Res is less of an issue.
Wedding Xania positions herself as the premier Wind healer for Imperial Onslaught with Freeze Res, as she packs healing with both of her Skills. For parties that opt to run a single healer, prioritize Wedding Xania over Lowen.
Alternate Team Members
An A-grade autobattle support, Sylas has team buffs, decent Strength, Last Recovery, and of course Freeze Res. Aeleen is still the better pick strictly for Doublebuff uptime, but those running Lowen anyways will prefer the variety introduced by Inspiring Scent.
Wedding Aoi brings Sleep infliction and healing via her attack Skills, which helps support the party while remaining offensive at the same time. Freeze Res allows her to attack without worry.
Gala Ranzal is another great Freeze Res option for this stage, as Cyclone Blade is great at clearing the mobs and greatly damaging the boss alike.
The Nightstalker Wyrmprint allows Johanna to obtain full Freeze Res, allowing her to inflict great AoE DPS via her dual attack Skills and Slayer's Strength.