It's the climactic battle between good and evil, and nothing will ever be the same.
Tropes
- And the Adventure Continues: Jim, Claire, Nomura, Blinky, and Merlin leave with the rest of the Trolls to find a new home in New Jersey, leaving Stickler, Barbara, Tobey, and ARRRGGH! to stay and protect Arcadia.
- And This Is for...: After delivering the fatal blow to Gunmar, Jim's last words to him:Jim: For Draal.
- Armor-Piercing Question: "What's your excuse now that you have your soul back?"
- Babies Ever After: Having freed the familiar children Walter and Barbara will now have to raise them as some of them, if not most, are from another century.
- Played with in Chompsky's case; the "baby" he and his doll wife is a peanut.
- Backup from Otherworld: AAARRRGGHH!!! uses the sooth-scryer to summon the past trollhunters to help fend off the gumm-gumms in trollmarket.
- Bittersweet Ending: Gunmar and his army have been killed after centuries of causing conflict and Morgana has been banished to the Shadow Realm, the supposedly only means of entering and leaving it (the Skathe-Hrün) destroyed. While the existence of trolls has been revealed to the humans of Arcadia, Janeth's reaction to the good trolls implies that the future regarding this will be bright, or at least not ending in disaster. With that said, Jim is still trapped in his troll-form with no hope of turning back, forcing him to abandon his human life - including his mother and his best friend - to go with Merlin and the rest of the trolls to set up a new Trollmarket in New Jersey now that the old Heartstone has been destroyed. Strickler and Nomura now have no hope of regaining their human lives since their familiars are now out of the Darklands, and many of said familiars are left with no families to return to since many of them have been there for literal centuries. On a more positive note, Claire goes with Jim and the trolls on their journey to New Jersey in addition to both telling Toby that they'll see him again and AAARRRGGHH!! staying in Arcadia to keep Toby company. The world is safe—for now.
- Boss Rush: They manage to defeat Gunmar (along with his army), Anger Rot and Morgana all within the span of this episode.
- But Now I Must Go: With the day saved, but the heart stone dead and thus Trollmarket lost, Jim travels with the trolls to find a new home in New Jersey. Though it's not all bad as Claire is also going with him.
- Call-Back: "I still don't like you."
- The Cavalry Arrives Late: Merlin does not get his powers back till after Morgana and the Gumm-Gumms have been defeated.
- Continuity Nod: Claire recites the ending to Romeo and Juliet with Jim in her arms.
- Death by Irony: Gunmar's death is quite similar to that of his son's, after getting fatally stabbed light erupts from his body and he turns to stone which is then shattered.
- Grand Finale: Of the series. Just in time to make way for 3Below.
- Heel–Face Turn: After being reminded of who he was, Angor Rot uses the chance Morgana to free Jim to instead attack her and free Jim.
- Heroic Sacrifice: Angor Rot grabs Morgana so that Jim can impail them both. Sadly, Morgana is not so easily slain.
- I Choose to Stay: Jim has Toby stay behind in Arcadia to protect it while he's gone. So Toby doesn't have to be alone, AAARRRGGHH!!! chooses to stay in Arcadia with him rather then go with Jim and the rest of the trolls.
- Irony: Morgana's defeat was won with the help of her most trusted champion (Angor Rot) and a tool of her own creation (the Skathe-Hrün).
- Kamehame Hadoken: Morgana was able to incapacitate everyone (except Jim, who blocked her attack) with one massive beam.
- Keystone Army: After Jim cuts through Gunmar, the energy blast destroys the remaining Gumm-Gumms.
- Made of Iron: Morgana was able to survive a severe physical ass-kicking from Claire and AAARRRGGHH!!! and even gets impaled with the Eclipse Sword with with no signs of slowing down.
- No-Sell:
- Gunmar tries to steal Jim's soul, and this time instead of blocking with his helmet, Jim simply reverses it.
- Jim tries to impale Morgana with Daylight, but she is unaffected and simply shatters it.
- Offscreen Moment of Awesome: After the battle, Steve is shown wielding a Gumm-Gumm spear with no real explanation of how he managed to get it.
- Open-Minded Parent: Claire's parents think of her going with Jim as "some time abroad."
- Percussive Maintenance: Chompsky figures out that hitting the cradlestone against the ground activates it.
- Pre-Mortem One-Liner:Gunmar: [fatally wounded] No... It cannot be!!
Jim: It is. - Red Is Heroic: The Gumm-gumms that become possessed by the trollhunter spirits turn from green to red.
- Sealed Evil in Another World: Since the trollhunters had no means of killing the Nigh-Invulnerable Morgana, they instead managed to banished her to the Shadow Realm and proceed to destroy the (so far) only foreseeable means of entering and exiting it (the Skathe-Hrün), banishing her from the Earthly plane and undoing the Eternal Night,
- Single-Stroke Battle: Jim counters Gunmar's attempt to take his soul and then quickly lands a single small cut, which is all Eclipse needs to destroy Gunmar, killing all the Gumm-Gumms in the process.
- Taking the Bullet: Jim jumps in the way of Morgana’s barrage attacks, defending his incapacitated friends from them.
- Wrecked Weapon:
- An attempt to impale Morgana with Daylight results in her laughing it off and shattering the blade, although Merlin repairs it when the battle is over.
- In order to defeat Morgana once and for all, Claire throws her into a shadow portal and then has Toby destroy the Shadow Staff so Morgana will be trapped in there forever.
