Istal is the peaceful, sacred ground of the Druids, the same place where Hendrickson was born and raised until he was kicked out for slacking off his duty. The sacred land was later invaded by trolls and their queen, until Bartra Liones sent the Seven Deadly Sins to aid the Druids.
[Episode 122] Druid Sacred Lands
10 years ago, around the time of Zaratras’s murder, Merlin separated Meliodas from his power as he was about to go berserk from seeing his lover’s grave injuries. She now plans to give it back to him.
[Episode 123] Test of the Druids
Meliodas and crew meet with the leader of the Druids in Istal who already seems to know the purpose of their visit.
[Episode 124] The Test Begins
Meliodas and Elizabeth follow Zaneri to the Tower of Trials.
[Episode 125] The Vanished Kingdom
Meliodas’s trial has begun. His test: The death of Liz.
[Episode 126] Repeating Farewells
Meliodas witnesses Liz’s death over and over again, losing himself to his wrath each time. Will he be able to pass the test?
[Episode 127] Promise to a Loved One
Worried Meliodas may be over exerting himself, Zaneri suggests he give up. Meliodas won’t back down, however.
[Episode 128] Yesterday’s Enemy
The group follows Jenna to the Training Grotto where they have an unexpected encounter.
[Episode 129] The Tattered Trio
After meeting with Hendrickson, the group discovers something else and hurriedly heads for the entrance to the Training Grotto.
[Episode 130] Farewell, Beloved Thief
After parting ways with King at the Fairy King’s Forest, Ban encounters his long lost past.
[Episode 131] Training Preparations
Training finally begins under Jenna’s guidance. Everyone is pumped up, but King says he’s not in the mood and stays out of it.
[Episode 132] What We Need
The group heads into the Training Grotto. What sort of training awaits them?
[Episode 133] Change in Strategy
The group must form teams of two, each team taking down one enemy. Howzer and Gilthunder are paired up once again. Will they be able to win this time?
[Episode 134] Doll Fight
Gowther is paired with Arthur. How will the king and doll perform?
[Episode 135] Growing Suspicions
King changes his mind and decides to enter the Training Grotto. He objects when told that only groups of two may enter.
[Episode 136] Distant Ally
King is suspicious of Meliodas. The cracks begin to show, perhaps more so because of the time they spent together as [The Seven Deadly Sins].
[Episode 137] Regained Power
The group safely finishes their training. Meliodas requests Jenna to return his power.
[Episode 138] Countdown
After regaining his power, Meliodas asks Merlin to send him to where [The Ten Commandments] are for a brief moment.
[Episode 139] Training Results
Meliodas returns safely after saying hello. Elizabeth also finishes her training and rejoins the group.
[Episode 140] Farewell
Having accomplished their goal, Meliodas and crew prepare to leave Istal.
[Episode 141] End of Training
Elizabeth is sad that her training hasn’t amounted to much. Thanks to Meliodas’s words, Elizabeth cheers up.
[Episode 142] The Last One
Meliodas has regained his power and everyone else has become stronger too. What is their new objective?
Read more at: https://nanatsu-no-taizai.fandom.com/wiki/Istar