That Time I Got Reincarnated as a Slime or simply Tensura redefines isekai power scaling with a intricate hierarchy of dragons, demons, and godlike beings. It is based on a light novel of the same name, and I belive it is one of the most addicting, and noteworthy anime series.

Based on anime canon (Seasons 1–3), this ranking will take into account feats, narrative weight, and lore to spotlight the apex predators of the Central World. Also, pleasse note I am only including the characters of Tensura which are known in anime only. So, the characters like, Michael, Velgrynd, Chloe, Velgrynd etc will not be included.

Let’s break down Rimuru Tempest powers along with other primary characters of the series. Rememeber, I am taking into account the final powers as per the latest chapters of the light novel and web novel.

7 Most Powerful Characters in Tensura (Slime)

Rimuru Tempest

Rimuru Tempest powers are basically the result of continuous evolution, and his top notch skills like Gluttony (at the start known as predetor, and later Beelzebuth, Lord of Gluttony). He was a middle aged white collar employee in twenty first century Japan. He got killed while saving a girl, and reincarnated as a Slime in a world of dragons, demon lords, and monstors.

At the end of the novel he becomes the ultimate being (only one at Multiversal level, apart from Michael when he abrorbed the cores of two true dragons) surpassing all true dragons, anicient demon lords, and others. He can use the power of turn Null to destroy reality. Also, he can swallow entire dimentions using Azathoth. Still, his story is no short of struggles, and building a peaceful world where everyone is free with plenty.

• Species: True Dragon / Demon Slime

• Role: Founder of Jura Tempest Federation, Demon Lord

• Defining Power: Predator → Beelzebuth → Azathoth (void manipulation). Absorbs skills, regenerates from subatomic particles, and controls space-time.

• Anime Feats:

  • Devoured the Orc Lord, gaining Starved and 500,000 souls. He also gained a demon lord seed which was essential for his promotion to a true demon lord.

  • Annihilated Demon Lord Clayman in seconds post-awakening. This battles was a combo of witts, and brawn. The defeat of Clayman also paved Rimuru’s way towards becoming a true demon lord. He also got to name the new demon lords (Octagram).

  • Survived Milim’s planet-shattering punch. He was almost gone if not the untimely entery of Veldora the storm dragon – a sworn brother of Rimuru, and uncle of Milim Nava.

• Why Top Tier? Rimuru Tempest Powers are a result of evolution from slime to True Dragon. All his close companions/fellows also got stronger due to his direct connection with them. Basically, he named them all so, a direct connection was automatically built.

Velzard

In the anime Velzard is seen as the second in command, and in a close relationship with Guy Crimson. She is the storngest of the living true dragons – which are said to be the natural calamities if go berserk. Currently she is at a low multiversal level seond only to a few key characters. She can affect countless dimentions with her powers. Truly deserving of one of the strongest characters in Tensura slime world.

• Species: True Dragon (Ice Dragon)

• Role: Guy Crimson’s Partner

• Defining Power: Absolute Zero manipulation, weather domination. Strongest ice magic user.

• Anime Feats:

  • Frozen continents during ancient wars (lore).

  • Stalemated Guy Crimson for millennia.

  • Implied equal to Velgrynd (Scorch Dragon).

• Why She’s Underrated: Minimal screen time, but as a True Dragon, she outscales 99% of the cast.

Veldora Tempest

The sworn brother of Rimuru, and Guradian deity of the Jura Tempest, Veldora Tempest is one of the strongest True Dragons. Overall, only a few can match his strength. Presently, he is at a Low Multiversal level with chances of becoming Multiversal soon.

• Species: True Dragon (Storm Dragon)

• Role: Guardian Deity of Jura Tempest

• Defining Power: Storm Magic, Dragon Haki, Faust (probability manipulation). Near-immortal; reforms after death.

• Anime Feats:

  • Destroyed nations pre-sealing (300-year rampage).

  • Tanked Milim’s punch meant to kill Rimuru. And felt only a minor pain.

  • Kamehameha-style Breath Cannon vaporizes mountains. Inspired by reading mangas while residing in Rimuru’s stomach space.

• Why He’s Fearsome: Embodies disaster—countries fear him. Rimuru’s only equal in banter.

Guy Crimson

Guy Crimson is the strongest pure demon on the list who is currently at a Low Multiversal level like Milim Nava. He is one of the seven primodial demons like Diablo. Even in anime (currently) one of the strongest demon lord would have to die a million times before killing him once. I am particularly excited about hus upcoming battles. Hopefully, we will see one in the fourth season of slime.

• Species: Primordial Daemon (Rouge)

• Role: Oldest Demon Lord, Octagram’s Leader

• Defining Power: Idea Nullification (erases concepts), Absolute Barrier (traps True Dragons).

• Anime Feats:

  • Contained Milim and Veldora’s clash during Walpurgis.

  • Commands deference from all Demon Lords.

  • Body harder than diamond; no combat damage shown (implies invincibility).

• Why He’s Elite: Controls narratives without lifting a finger. Fear hierarchy: Guy > all.

Milim Nava

Another most powerful character of the entire series is none other than the dragonoid/demon lord Milim Nava. A seemingly harmless character, but with the power to shatter huge plains with just one puch. So, is Rimuru stonger than Milim? If you’re following anime, then no. But according to the novel, yes, Rimuru becomes far stonger than Milim at the end.

Milim is only second to Guy Crimson, an ancient demon lord (in the anime). However, if they go toe to toe, Guy will not come out un-scathed. At present she is at Low Multiversal level  (in light novel/webnovel) surpassing most known characters.

• Species: Dragonoid / Demon Lord

• Role: “Destroyer,” Octagram’s 2nd Seat

• Defining Power: Drago Buster (energy blasts), Wrathful King Satan form (physical god mode). Immune to magic below Ultimate level.

• Anime Feats:

  • Obliterated Eurazania’s capital in a tantrum. Although, she was trying to trick Clayman. Nonetheless, it shows she only have a blank space instead of a brain.

  • Fought Veldora to a standstill. It happened when Rimuru was trying to win a duel with Clayman during the demon lord meeting. It was not a serious fight between Milim and Veldora.

  • Casually oneshotted Charybdis. Yes, she did it with only one basic move when Charybdis attacked the Tempest. (a scheme of Clayman)

• Why She’s Here: Raw destructive power surpasses all but Rimuru. Her childlike whimsy masks catastrophic potential.

Diablo

The main guy of Rimuru, Diablo is one of the most loyal servent of the Slime. If not for his picky nature (prefering quality of the master he’ll serve) he would be the strongest or atleast on par with Guy Crimson in anime. Still, in light novels he is one of the most mysterious, and powerful characters, worthy of being on my list.

With a frgament of powers like Null (give by Rimuru) he can go toe to toes with any character on this list.

• Species: Primordial Daemon (Noir)

• Role: Rimuru’s Butler

• Defining Power: Tempter (mind control), Azazel (barrier creation + thought acceleration). Analyzes/counters any skill.

• Anime Feats:

  • Solo’d Falmuth’s army + Holy Knights effortlessly. It was a one sided battle.

  • Fought hero Shizue evenly (while holding back). He didn’t even have a name yet.

  • Implied to rival Guy Crimson in antiquity. Being one of the seven primodials.

• Why He Matters: Rimuru’s “trump card.” His loyalty is the series’ greatest power flex.

Chloe Aubert

Although, we don’t see her in anime but this list of the most powerful characters in slime wouldn’t be completed without her. There were references about her. Yes, she is the one who sealed the Storm Dragon Veldora in the first place. Although, she is not yet revealed or discussed much in the anime.

• Species: Chronoa (Time-traveling Hero)

• Role: Guardian of History

• Defining Power: Yog-Sothoth (space-time control), Infinite Prison (seals even True Dragons).

• Anime Feats:

  • Trapped Veldora in a time loop (pre-Rimuru).

  • Stole skills via Usurper.

  • Exists across timelines simultaneously.

• Why She’s Overlooked: Her power peaks in later arcs (LN), but anime hints at her multiversal relevance

Power Comparison Table

Why Power Scaling Matters in Slime

Unlike typical isekai, Tensura ties strength to evolutionary hierarchy:

• True Dragons & Primordials: Exist beyond magicules; manipulate physics (time, concepts, entropy).

• Demon Lords: Power via souls (Harvest Festival) or birth (Milim/Guy).

• Human Limits: Hinata Sakaguchi (excluded here) peaks as a “Divine Human”—proof humanity can rival monsters with skill. The only human that surpases her is Chloe Aubert. And in a way Rimuru Tempest who is a human at heart and soul.

My Thoughts on Most Powerful Characters in That Time I Got Reincarnated as a Slime

That time I got reincarnated as a slime brings a slice of enjoyment, fun, and continuous power evolution. Such, anime is rarely seen now a days. Even I have watched the series atleast 4 times, and waiting for the next season four. I hope they release the season 4 soon.

Rimuru Tempest powers are a balance of offense, and defense. But the most powerful trick up his sleeves is always his intellect, and planning. The intelligent system or the voice of world at his disposal are one of a kind giving him an extra edge in each battle or conversation.

The world building and charcter development in Tensura are no short of a master piece. However, too much happy times, marry making, and no note worthy incidents (just like in the last season) may drop its popularity.

Slime’s power system rewards cunning as much as strength. Rimuru’s ascent—from eaten slime to multiversal deity—mirrors the series’ ethos: power is taken, not given. Yet characters like Diablo and Guy remind us ancient beings play chess while others brawl. Thanks for the Read!!

Read about Rimuru Tempest Powers and abilities HERE.