Megalomaniac
Episode: 1x01 | Airdate: Feb 28, 2016 (5 min)
Frisk confronts Sans in the judgment hall, but it seems like Chara is still in control.
Episodes
Yet Darker
Episode: 1x02 | Airdate: Mar 19, 2016 (8 min)
When Frisk enters Waterfall in Hard Mode and meets with Sans to go to Grillby's, the glitched state of the timeline allows Gaster to will himself back into existence. He then attempts to take Frisk's soul, forcing Frisk and Sans into a battle with him.
don't forget...
Episode: S01 Special | Airdate: Mar 25, 2016
*Determination
Episode: 1x03 | Airdate: Apr 2, 2016 (7 min)
Due to the glitched state of the timeline, the previous reset by Sans causes Chara to return. Chara tries to steal Frisk's Determination, forcing Sans and Flowey to team up to stop him.
Your Best Friend
Episode: 1x04 | Airdate: May 2, 2016 (9 min)
Sans, Flowey, and a returning Gaster work together to defeat Chara.
Continue
Episode: 1x05 | Airdate: Jun 24, 2016 (17 min)
Asriel, with the power of seven Human souls, fights a HATE-possessed Chara in a final showdown.