Battle Lines is the 18th episode of Bakugan: Mechtanium Surge. It aired on June 19, 2011.
The episode begins with the Gundalian soldiers fighting back against the Chaos Bakugan. It seems that the Chaos Bakugan are defeating a huge amount of Gundalian Bakugan. The Gundalians then try to get revenge on the Chaos Bakugan and are starting to gain the upper hand but suddenly, all of them are all defeated by a Aquos-Darkus hybrid Cyclone Percival and a Pyrus-Darkus hybrid Iron Dragonoid owned by Sellon and Anubias. When they finished off the Gundalian's Bakugan, Anubias wondered where Dan is.
Back at the base in Gundalia, the battle brawlers find out that the Chaos Bakugan are all heading to the city area, where there are Gundalians defending the area such as Mason and Jesse. Ren concludes that they are properly heading to Neathia so they can invade them next, as there is a Dimension Transporter in the area. They also think Mag Mel is hiding underground in his castle while he commands the Chaos Bakugan to attack Gundalia. Paige is eager to initiate a sneak attack but Captain Elright reminds her how the previous attempt ended. Dan insists to fight against Mag Mel but Marucho tells him not to, calling him a liability. Dan gets extremely frustrated and grabs Marucho by the collar and yells at him, that he has saved him over the past few years. He didn't stop until Rafe told him that it was enough. The group except for Dan leave as they hear that the Chaos Bakugan were invading the city lines. Taylean is on Zoompha while Shun is thinking.
The city is under fire as the group continues to fight off the Chaos Bakugan. Dan then experiences another vision which shows Mag Mel telling Dan to surrender the Gate and Key, he desires. Dan then remember the phrase from the woman that they fought on New Vestroia before. They then leave by themselves on Zoompha but are interrupted by Shun and Taylean. Shun then asks what Dan is doing here and flips him. He then lectures him that he didn't change while he went to New Vestroia and then asks him to come with him. Dan gets up and then flips Shun.
They then begin to fight but are attacked by an Army of Chaos Bakugan led by Anubias and they destroy both Titanium Dragonoid's and Taylean's Mobile Assault, Zoompha. Dan then uses BakuNano Sonicanon and they fight back alongside Shun. They are doing very well and defeat a large amount of Chaos Bakugan, but then Anubias summons Mizerak and Venexus, so Dan and Drago summon Zenthon. Drago and Zenthon fight Miserak and Venexus but a swarm of Chaos Bakugan go after Drago, so Shun decides to use Hammermor and they fight them back. Later, Anubias summons Smasheon and defeats Taylean which hurts Shun. Dan, Drago, and Zenthon then summon Zenthon Titan for extra help. He then fights against Smasheon and Venexus. Titanium Dragonoid then defeats Miserak with his Wonder Superior attack but Sellon arrives out of nowhere and summons Deezall, Rockfist, and Braxion. They continue to fight and Drago defeats Braxion with the same attack easily. When Deezall and Rockfist are about to try to defeat Zenthon Titan they are both defeated by a long range shot by Marucho and Trister with Cannongear who hacked Rafe's Mobile Assault to use as a Cannon and upgraded it's power for Mechtogan targets. Smasheon then gets defeated by Zenthon and Venexus is easily defeated by Zenthon Titan. Anubias then faints because of the power needed to control three Mechtogans at a time. Sellon then carries him and teleports back to Mag Mel's Castle.
Dan begins to thank him but Marucho gets angry because he did not follow his orders as Team Leader. Dan and Marucho then argue but then Ren messages Marucho that they cannot find Paige and Rafe. They then think that their gone after Mag Mel and they find them trying to sneak into Mag Mel's Castle just as they thought. The group begin to argue, but a Ventus Flash Ingram blasts them and they fall into a chasm below.
- Titanium Dragonoid
- Razenoid (cameo)
- Iron Dragonoid
- Cyclone Percival
- Flash Ingram
- Infinity Trister
Mobile Assault Debut
Mobile Assault Seen
Mechtogan Titan Seen
- This is the first episode where Mechtogan of all six Attributes are shown in a single episode.
- This episode exhibits the power of a Mechtogan Titan even better than their debut episode; six regular Mechtogan together were unable to topple Zenthon Titan.