The Legendary Stag is a Trial found in the Chamber of the Fallen in Final Fantasy Brave Exvius. It will be released soon into the Global version. Player's face the Boss Elafikeras.
Battle[]
At ELT Elafikeras has 80 million HP, but low DEF and SPR at 45 and 15 respectively. Elafikeras has a rather limited movepool and should not be a threat as the goal of the battle is to destroy him quick before he can unleash his truly powerful attacks.
The Boss will mostly act only once per turn. Its first move will always be Sparkling Horn which restores MP to the party for 8 turns. After that it will always use Charge (Physical Damage x3 to all units).
As Elafikeras is weakened and passes some thresholds it uses other attacks. At thresholds of 75% and 50% it will use either Multi Horn or Demon's Stone (a x6 Physical and Magic Damage ability respectively on all units). If attacked with a Spell (namely Black Magic, White Magic, etc.) it will use Multi Horn, if not then it will use Demon's Stone. At 30% it will use Menacing Stampede which decreases ATK/DEF/MAG/SPR by 50% for 3 turns to all units.
Finally if 8 turns pass, Elafikeras will use Supersonic Thanatos to inflict Instant Death to all units, followed by The giant horn drains all!! (Magic Damage x5 as MP Drain to all units and inflict fixed 99,999 damage to all units and restore itself back to full HP) using this ability twice.
Elafikeras has a Wind weakness (-50%) an Earth Resistance (300%), vulnerable to Disease and susceptible to ATK/MAG Breaks.
Battle[]
The battle against Elafikeras is rather simple as it is a mere race against time to defeat it before it can render the battle unwinnable. The player 8 turns to make this happen. Fortunately, Elafikeras' low defensive values make this endeavour in fact quite easy to achieve.
It is recommended the player uses Magic Damage given the Boss' low SPR. Shantotto and Barbariccia are the options to go due to being able to Dualcast Tornado creating a giant chain that will deal lots of damage to the Boss, alternatively a pair of Lunera (awakened) can also do the Job with Aureole Ray. For good measure a finisher with Wind abilities can also be used. Shantotto, Barbariccia and even Hope (albeit awakened) with Aeroja can also do this job. In case of Shantotto and Barbariccia they can combine a Tornado with an Aeroja in their Dualcast.
Other strong attackers like Kunshira or Blossom Sage Sakura can also get the task done. In the latter's case although it doesn't inflict Wind damage her Quick Final Thunder can grow sufficiently strong over time to inflict great damage, although she may need to have a rather high 1000 MAG value to make this work properly.
Although Physical Damage or non Black Magic attacks can be used, they usually are not recommended. The former because the Boss has higher DEF than SPR, plus not many physical attackers can take advantage of the Wind weakness effectively, also because not attacking with a Spell causes the retaliatory threshold attack to change which in turns changes the defensive measures needed.
For defensive purposes all the player needs is break the Boss' ATK/MAG, a Physical Tank and a decent buffer. Warrior of Light is excellent because of his debuffs and The Light is With Us, plus his overall bulk should allow him to live (with Mechanical Heart equipped a Healer won't be necessary). For buffs Soleil or some of the commonly used bards like Ramza, Lunera or Roy will suffice.
A healer will not be needed with a setup sturdy enough, but one can be brought for good measure.
Overall the battle is not truly difficult and depends on the player having the necessary elements to properly race the Boss, which by the point the player faces this Trial should be of easy acquisition.