You can get easily plant killer from Ifrit 2 Stars and treasure chest on Mystic Woods
You need to be able to debuff Antenolla’s Atk (no resistance), try to have a character who can debuff multiple targets at the same time (example: Cloud of Darkness). If you don’t have the area debuff, then make sure you try to inflict break attack (especially full) on each target every turn
Strong Single Target Skill.
It may seems better to use AOE, however you want to focus on killing each part one by one because if you accidentally Damage the flower too much, it will trigger very powerful AOE attack that may cause you unnecessary trouble on this battle. Example: Luneth Hit through, Lightning Crushing Blow, etc
This battle is not mage friendly.
Try not to use mage here because they usually have lower defense, especially if your mage only know elemental spells, because Antenolla has a lot of elemental resistance (depends on the part), the only safe element is earth, dark, and light
Have a character that able to cure ailments
Antenolla can inflict a lot of ailments, so a character that can undo that (or simply bring recovery items) is very useful. Especially Cloud of Darkness, his Comeback Skill can cure the whole party bad status. Make sure your healer resist against paralyze, so it can cure others ASAP.
Hero that has draw attack ability
Provoke wont work because on the turn you use provoke, I believe that hero will be dead. However, the hero with draw attack will lure the attack and also make the antenolla absorb that character MP, this is really important to protect your healers. Remember always use guard on every turn. This tactic work well if you bring Cecil (or other protector), Cecil will protect the decoy and get the damage mitigation.
Example: Amarant, Leo, Galuf, Medius, etc
MVP for this battle
Cloud of Darkness, Luneth, Refia, Leo/Amarant, Cecil/WoL/Charlotte
Each part has 580,000 (twice the Japan version)
The only safe elements are Earth, Dark, and Light
1st turn make sure you buff your defense (Protectga/Cheer/Embolden). After that debuff Antenolla’s Attack and then begin attacking the part one by one.
Ivy => Root => Leaf => Flowers
===Watch the video for step by step explanation===
Recommended Items to Bring
Turbo Ether, Mega Ether, Elixir, Unicorn Horn, Smelling Salts, Antidote, etc.
Reward: Thorned Mace (Atk +78, 70% chance of poison, Man Eater Ability)