"Dragon Ball Super" episode 21 brings in more action with its trailer showing how Frieza and his army of 1000 soldiers attack Z-fighters, who will do whatever they can to protect Earth.

In the trailer uploaded on YouTube by Pixel Planet, Frieza unleashes his army to a battle with Z-fighters, who seem to be crippled by the absence of two of their most powerful comrades: Goku and Vegeta.

According to Design 'n Trend, there are three things this episode is expected to deliver, including a meaningful feat from support characters Krillin and Tien. It will also address why Goku and Vegeta are not with them in battle and why Frieza would not lift his behind off of his throne to engage in a fight with Gohan.

Those who want to watch the episode without any knowledge of what they will face should take the nearest exit now because the rest of this article will most probably spoil it for you.

According to the report, Krillin and Tien take on most of Frieza's minions, much to the surprise of many, despite the fact that Gohan, Goten, and Piccolo are with them.

This makes it the first meaningful thing the two characters did in a decade that made them appear as "legitimate heroes" because since the beginning of the Saiyan saga, they have become an almost permanent liability to their comrades.

"The soldiers are so weak that Krillin and Tien should be able to fight many of them off and look like legitimate heroes for the first time since the Saiyan Saga," the outlet explained.

The second thing to be expected in the episode is Goku and Vegeta's absence because they are undergoing training with Whis on a distant planet.

Because of this, the two formidable warriors would not be able to join the battle -- at least not until the end of episode 21, says the outlet.

"Training means everything to Goku and Vegeta, and the two warriors won't let something as trivial as Earth's impending destruction interrupt it," it reads.

Finally, Design 'n Trend believes Frieza would not engage in battle even with the powerful half-Saiyan Gohan because he would be saving it for Goku and Vegeta "since Frieza is the main villain."

"He's somehow become strong enough to fight evenly with Goku and Vegeta, there is no reason to think that we'll see the intergalactic tyrant get out of his floating space throne," the outlet explained, adding that if the villain already fought before the two Saiyan arrive then the episode would come at an early end.

Check out the episode preview below and tell us what you think.