I'm running the following party through the event on Hard:

Cloud (Front Row, lvl 50, 4* Crystal sword, Genji Shield, Hyper Wrist), with Double Strike and Drain Strike
Sephiroth (Front Row, lvl 50, 5* Gladius+, Diamond Armor, Hyper Wrist), with Double Strike and Blade Bash
Terra (Back Row, lvl 50, 4* Gravity Rod, Genji Helm, Earring), with Fira and Blizzaga
Lenna (Back Row, lvl 45, 4* Light Staff, Summoner's Robe, Angel Ring), with Curaja and Haste
Rydia (Back Row, lvl 50, 5* Ice Whip, 4* Black Cowl+, Earring), with Thundara and Thundaga

For Anima, I focus attacks on the main body. Use Lenna to heal if needed, or Haste Cloud and Rydia when healing isn't vital. Cloud and Sephiroth unload Double Strikes, Terra drops Blizzaga, and Rydia either uses her SB (Shiva), or drops Thundaga and Thundara on the main body.

I get probably 3-4 rounds of attacks in before Anima goes down.

For the Beta Behemoth and the Manasvin Warmech, I focus on hasting Rydia and using Thundara and Thundaga to make quick work of them.

For all of the other encounters, I auto-battle through them, keeping an eye on health levels to see if healing is needed.

When I run into Anima earlier than the final battle, things get a little rough (it's happened 3 times, and I died one of those times), so don't give up on Hard, it's just really rough when you hit Anima more than once (although the rewards are nice).