WARNING: The following contains spoilers for Episode 41 of That Time I Got Reincarnated as a Slime, "The Eve of Battle," now streaming on Crunchyroll.
Rimuru Tempest has long since learned how to survive in his new isekai world, but several challenges remain, such as the large distances involved in trading with or fighting against other nations. It took days just to arrive at the Armed Nation of Dwargon while riding a direwolf, and Rimuru's army, though powerful, cannot be everywhere at once.
Luckily, Rimuru's human alliance is complete -- just as Demon Lord Clayman begins his march to the Animal Kingdom of Eurazania. It seems impossible for Tempest to defend its ally, but Raphael, formerly the Great Sage, offers a solution that could change the entire narrative of Reincarnated as a Slime.
Rimuru's strongest allies cannot reach Eurazania in just two days' time to intercept Clayman's invading army of 30,000 troops. He also deduces Clayman's true goal: to slaughter everyone in Eurazania to fuel his ascension into True Demon Lord status, just as Rimuru once did. He laments the sheer distance involved in this campaign until Raphael, one of Rimuru's "Ultimate Skills," privately offers a solution -- the kinks halting his potential teleportation magic have been fixed.
Powerful individuals like Rimuru and Benimaru can create anti-magicule barriers to shield themselves from the dangers of teleportation, while Rimuru can also use the Control Space spell to teleport other parties. With this new ability, Rimuru sets to work evacuating everyone in Eurazania while his orc allies build refugee camps to house everyone. Now Eurazania is empty, and Rimuru can teleport his united army there to battle Clayman's own with no risk of innocent casualties.
Rimuru's new teleportation strategy has several implications for Reincarnated as a Slime. With this ability, he can instantly arrive at any nation's capital city to parley with foreign politicians on a moment's notice, or bring guests to Tempest just as quickly. This also allows news to travel much faster, as Rimuru can teleport himself and/or his allies to another nation's court to hear an update. Ordinarily, leaders must send messenger pigeons or couriers to deliver news and negotiate with other nations -- but not if teleportation magic is involved.
Another turning point is that Rimuru can immediately confront any enemy across the entire continent, without taking the time to march to a foreign battlefield and navigate rough terrain. With the correct intelligence, his army can intercept an enemy to protect Tempest and its allies, or attack a hostile nation right in its heartland. The problem of supply lines is also eliminated, since Rimuru can teleport much-needed war materials to the front lines with unmatched speed.
This could make Tempest nearly unbeatable in conventional warfare, but this spell is not necessarily unique to Rimuru. An enemy Demon Lord or other party may invent similar magic -- if they can create anti-magicule barriers to protect themselves. Episode 41 of Reincarnated as a Slime sees Tempest more powerful and newly advanced than ever, but this strength often inspires mistrust and hostility from others, such as the Western Holy Church. Rimuru must take care that he does not overuse this magic and prompt his enemies to use this strategy against him.
