In the case of insufficient spiritual attributes, forcibly controlling powerful undead creatures will face the risk of losing control of all spiritual imprints, and will permanently damage their own spiritual attributes, which Rod will naturally not do.

Due to the lack of spiritual attributes, in order to control the Nethersea Monster, Rhodes made his own decision long before using the elemental core to dive into the deep sea.

Relying on the existing means alone, Rhodes could not improve his mental attributes to the point where he could control the sea monster in a short period of time, so Rhodes could only start from other aspects.

Previously, Rhodes did not control the legendary-level undead creatures, if it was controlled purely by attributes, according to the experience value correspondence, Rhodes needed at least 400 points of control of spiritual attributes to control the sea monster, which is obviously difficult to achieve.

Legendary-level undead creatures are obviously not controllable by ordinary necromancers, and the only ones who can effortlessly come up with so many manipulative spiritual attributes are real lichs.

In order to retain the magic immunity on the sea monster's body, Rhodes was destined to be unable to use the Ghost King's cloak to transform it, and had to find a way to control it from other aspects.

Rhodes' final decision was to use the ability of the Mother of Souls to directly control the sea monster, and then give orders to the sea monster by controlling the Mother of Souls.

The crown that Rhodes obtained from Nags happened to be inlaid with a high-quality Mother of Revenants, which could be included in the spatial ring along with the crown due to treatment, and was erased from its own consciousness, which happened to be used by Rhodes at this time.

After controlling the Netherworld Kraken with the help of the Mother of the Revenant, Rhodes was unable to gain any experience points from the Kraken for a short period of time, and when Rod had enough control spirits, he could still find a way to reimpose his own spiritual imprint on the Kraken.

After taking control of the sea monster, Rhodes used its power to explore the vast whirlpool above the sea.

The spatial turbulence that pervades the outer periphery of the vortex cannot cause any effect on the tentacles to which the sea monster is magically immune, and it cannot leave any scars on the pale tentacles.

The large number of things of a completely different nature brought back by the tentacles from another dimension also proved to Rhodes the worst truth.

The area connected by the giant vortex is not only a specific space, but also a large number of unknown spaces, and the two tentacles of the sea monster that penetrated into the vortex at the same time can even appear in two completely different spaces, which are full of unknowns and randomness, and it is even more difficult to confirm the existence of the main plane from it.

The wreckage of the ship that appeared in the belly of the sea monster before gave Rhodes the hope of returning to the main plane, which also made Rhodes know that the inside of the whirlpool is full of unknowns, and he is unwilling to give up this possibility.

Towards the inside of the whirlpool, Rhodes sent a large number of bone fish kings, but because they were too far apart, Rhodes could not communicate with them, could not know the real situation over there, and even the tentacles of the sea monster through the whirlpool could not give back the information that Rhodes wanted to know.

In order to prove that the main plane is within the range of the vortex connection, Rhodes also thought of some methods.

The barrier of the spiritual imprint made it impossible for the Bone Fish King who passed through the whirlpool to carry out the orders given by Rhodes immediately, and what drove the Bone Fish King to continue to act was the last order they received before passing through the whirlpool, no matter how complicated the order was, as long as it was set in advance, they would carry it out to the letter.

To this end, Rhodes first made the Bone Fish King with his own spiritual imprint kill each other in the same space, until in a space, there was only one Bone Fish King left, and he was sure that it was an accessible space.

In this way, Rhodes was able to confirm that the whirlpool in front of him connected a total of five spaces suitable for ordinary creatures to survive.

As for some other areas, due to their harsh environment, as soon as the Bone Fish King arrived, he was instantly killed, which was not suitable for the existence of ordinary creatures at all, so it was not in Rhodes' consideration.

Due to the chaotic spatial turbulence shrouded in the outer periphery of the whirlpool, just passing through it smoothly is a big challenge for the Bone Fish King, not to mention the possibility of coming to the same space, in order to determine the existence of these five spaces, Rhodes paid hundreds of thousands of Bone Fish King's lives.

For the five surviving Bone Fish Kings, Rhodes highlighted them among his huge number of spiritual imprints.

The only remaining Bone Fish King in these five spaces, according to the initial order, as the beginning of the transformation of the undead, began to continuously expand the number of undead creatures, and led all humanoid creatures, or related beings, to the vicinity of the vortex where they arrived.

After all this is achieved, the Bone Fish King will choose to die on his own initiative to dissipate his spiritual imprint, and Rod, who is in the water elemental plane at this time, will let the Nethersea Kraken pass through the vortex with its huge number of tentacles, and pull everything around the vortex back to the water elemental plane where Rhodes is located.

Whenever the spiritual imprint of a Bone Fish King dissipates, the Nether Kraken will grab all its tentacles near the whirlpool, grabbing all possible things into the whirlpool, and even to ensure the possibility that the tentacles and the Bone Fish King are in the same space, Rhodes will let the Nether Kraken catch them a few more times.

For the exploration of the unknown, naturally it will not be as smooth sailing as Rod imagined, and Rod no longer knows how many irrelevant things the Nethersea Kraken has pulled back, from meaningless floats to monsters that are very different from humans, Nethersea Kraken has pulled back a lot.

Behind every failed attempt, there are countless bones and fish kings who have died, and once the spiritual imprint of the bone fish king in a certain space dissipates, in order to continue the exploration, Rhodes must let the bone fish king return to the original space, and this chance of crossing the vortex can only be filled with the life of the bone fish king.

On one occasion, the Nether Kraken pulled back a humanoid high-level creature with a whole body on fire, and the entire surface of the sea began to burn because of its arrival, if Rod was right, it should be a fire spirit that exists in the depths of hell.

Suppressed by the water elemental plane, the power of the flame elf was greatly reduced, and the Netherworld Kraken finally solved it, but Rhodes was quite vigilant in his heart, and he didn't know what unknown spaces were connected behind the whirlpool in front of him, and there would be creatures like the fire elves.

Fortunately, at this time, Kane's arrival made Rod feel a lot more at ease. This nobleman from Erathia also made Rhodes certain the possibility of returning to the main plane through the vortex.