Daggers are one of the best weapons for an AI team leader-- because the combo automatically includes dashing and moving, they end up naturally evading damage. The caveat is that injured Dagger users will charge recklessly into battle, so How To Flee Properly and Prometheus give Ezelith a bit more survivability. The success of a run will depend largely on whether she follows the boss, but thankfully, adds on this level tend to fall quickly or even cluster on the bridge.
While Vanessa will downed by Sleep periodically, her co-ability and strong multi-target damage make for an excellent teammate. If using a third melee Adventurer in place of Sinoa, her equipment can be toned down a bit as the three frontliners share damage.
Sinoa adds a random element to IO runs. Will she boost Defense, increasing team survivability, or will she boost Attack for quicker damage? It's a bit precarious, given she effectively takes the place of a second healer, but she'll be casting reliably thanks to Sleep res.
Bellathorna is added for a little more Buff Time, while Glorious Tempest has general Wind Res for added bulk. Greatwyrm Midgardsormr or any other defensive bonuses can easily be run in its place.
Verica's the sole healer of this team and thus comes double-equipped with Recovery Potency Wyrmprints. Beauty's Balm supplies another heal, but for defensive purposes, the Otherworldly Bough can also clear a circle around her. Regardless, her lack of Sleep Res isn't too much of a hindrance as a ranged Adventurer; bad timing may put her out when her heals are most needed, but the probability of failing a run due to this is low.
Alternate Team Members
Those who have Karl can run him in place of Vanessa for tremendous offense, Slayer's Strength, and good damage uptime. He has no defensive benefits to speak of though, so equipping Prometheus or bringing an extra healer may be necessary to keep this reckless Sword user alive.
Being powerful and sturdy with Sleep res, Naveed is an ideal team leader. Run him with Valiant Crown or Healing Doublebuff to get the most out of Radiant Bauble.
Sarisse can easily replace Sinoa for more offense-focused support. While Sleep Res also makes her a great replacement for Vanessa, having three ranged characters on the team often puts too much pressure on the melee frontliner.
If bringing another healer, Vixel is the top choice. While Verica can dodge Sleep pretty well thanks to ranged weapon, the added security of Sleep Res guarantees uptime for Vixel. This is pretty important since his Spirited Song has a somewhat high SP cost, and he'll want to cast Agitato Assault as much as possible to boost both his and Verica's healing.