The Mass Effect franchise has always been known for its riveting side character and interactive storyline, but many fans don't give the plethora of challenging villains throughout the series the credit they deserve. Thankfully, BioWare's Mass Effect Legendary Edition gave players a chance to jump back in and take down everyone from the Reapers to crime bosses all over again.

Fans don't yet know what enemies wait for them in the hitherto-unnamed next Mass Effect game, but  BioWare's Twitter account has confirmed that another title is coming. Whatever trouble the galaxy faces next, it'll be hard to top the bevy of enemies seen in the first three Mass Effect games.

Reaper On Rannoch

Commander Shepard fights the Reaper on Rannoch.

When fighting the Reaper on Rannoch in Mass Effect 3, the players will be in a tight situation that will prove challenging to get out of. This method will prove difficult due to the strength and powers of this particular Reaper.

Related: 10 Best Characters in Mass Effect, Ranked By Design

The Reaper on Rannoch is a powerful opponent that has a firing chamber that can cause a lot of damage, and the only way to defeat it is by hitting this chamber in between shots. To do this, the player must let it target them first, so prepare to dodge as soon as possible when the time is right.

Sovereign

A Turian is controlled by Sovereign.

In the first Mass Effect, players are introduced to a galactic threat in the form of what appears to be a sentient ship. Sovereign, who players would later find out is in fact a non-organic being of immense power, had plenty of loyal Geth under its command. Alongside the Geth was the rogue Spectre Saren, who provided Sovereign with plenty of help.

Once Saren dies, Sovereign takes control of Saren’s dead body to attack Shepard. The fight is intense and challenging. Not only are Geth attacking the crew, but Sovereign can bounce from wall to wall avoiding the gunfire.

Saren

Saren standing in the Citadel.

Die-hard Mass Effect fans know that The Council was a pain to deal with and didn't take Shepard's warnings about Saren or the Reapers seriously at first. While players would learn about Saren’s powers through those who served him, they would finally get a chance to see how powerful he was at the Citadel.

Saren received “upgrades” from Sovereign that would later allow Sovereign to take control of Saren’s body, but he also assisted Saren while he was alive. Before Saren’s death, the player has to try and take cover as Saren circles the area on a hovering platform and the Geth pour in. Each makes things much more difficult for players and their crew.

Matriarch Benezia

Matriarch Benezia stnads in psychic energy.

After being brainwashed and under the control of Saren, Matriarch Benezia becomes a formidable opponent for players in the first game. Commander Shepard will encounter her before Saren, and the fight is a good indication of how difficult things will get with Sovereign's other servants.

An Asari, one of the fan-favorite alien races in Mass Effect, the powerful Asari Matriarch Benezia is a powerful opponent that uses her biotics and commandos against the player. When they hit the player, her biotics renders them immobile for a few moments and unable to use the weapon the player is holding, making it harder to get in good hits without getting frozen in place.

Praetorians

Praetorians during a battle in Mass Effect.

The Praetorian is a recurring enemy in both the second and third games and can be challenging to take down. With the amount of solid armor and the barriers that it has, this is one fight that players will end up getting frustrated over.

Related: 10 Best Weapons Upgrades In Mass Effect 1 Legendary Edition

The attacks that the Praetorian throws out are lethal. If the player or the crew is exposed to the particle beam that the Praetorian has, it can kill the player within moments. The Praetorian’s attack has a long range, and its ability to float gives it the upper hand in its movements and attacks.

Human Reaper Larva

Human Reaper Larva in Mass Effect 2.

During the final mission of Mass Effect 2, an enemy will loom over the player and their crew and is challenging to beat. This opponent is the horrifying Human Reaper Larva, the incomplete Reaper that the collectors were constructing in the image of a human being.

It will shoot projectiles and make it hard to dodge as it moves around. The Human Reaper Larva can duck under the platform when wounded. so, while worrying about teammates at a looming bomb during the final showdown, a giant machine is trying to kill the player, adding a bit of extra anxiety to the situation. The Human Reaper is notable not only for being a challenging opponent but also for the psychological damage it does to Shepard by, depending on what has happened earlier in the game, using his or her dead crewmembers for energy.

Shepard's Clone

Shepard facing his clone.

One thing that surprised players is that Commander Shepard has a clone. The encounter with the clone is part of the DLC "Citadel." In this DLC, the player faces one of Mass Effect 3's most challenging fights.

The clone doesn't just look like Shepard but also has the same class the player chose. This clone will mimic the player's close-quarters combat technique and is one of few chracters that can use medi-gel. The fight the player has to endure with the clone is brutal, and it doesn't help when they are on the same skill level as the original Shepard but can also use medi-gel, making the job of killing it even harder.

Tela Vasir

Tela Vasir holding a woman hostage.

Mass Effect 2 has a DLC in which the player can finally meet with the current Shadow Broker, but he is not the only challenging enemy that the player will encounter in "Lair of the Shadow Broker."

Related: 10 Most Important Choices Players Make In Mass Effect Legendary Edition

As part of the DLC, the player will also encounter the Asari Tela Vasir. She is a dangerous opponent that can knock a player out of cover with a shockwave and stun the player. With her strong armor and barrier, it takes a lot of firepower and patience to wear down her health.

Shadow Broker

Facing the Shadow Broker.

Upon meeting the Shadow Broker in DLC, the player finally gets to see the face behind the anonymous seller. It's great to finally put a face to the individual who sells valuable, often illegal information to the highest bidder. However, the meeting is not pleasant, and the player has to take him down.

After incapacitating a third teammate of Shepard's, the fight begins. The player will have to deal with the Shadow Broker and his abilities, as he charges at the player and can break the cover the player is using. He also constantly fires his Revenant, so almost nowhere is safe. He can also use his shield as a weapon against Shepard and the crew, making him one of the more diverse enemy encounters in the series.

Kai Leng

Kai Leng holding his sword.

Mass Effect 3 may have let some fans down with its final plot beats, but it's still filled with narrative-rich missions for the majority of its run. One of the missions is called Priority: Thessia, and it is considered one of the most challenging in the Mass Effect series as Kai Leng is there to welcome Shepard in a violent way.

Kai Leng comes equipped with his palm blaster and sword that is capable of Electric Slashes. He can use heavy melee attacks, and some of these attacks can kill the player instantly unless properly blocked. Kai Leng can punch holes in the floor to summon additional enemies, too. Though there are many memorable and powerful enemies throughout the Mass Effect games, none are more difficult to deal with than Kai Leng.

Next: 10 Best NPCs In Mass Effect Legendary Edition That Are Not Squadmates