Before transforming the hero Thunderbird into a Death Knight, one of the problems that Rhodes had to face was his lack of control spirit attributes.

Due to the high rank of the hero Thunderbird itself, after transforming it into a death knight, it needs to consume more spiritual attributes of the necromancer in order to form a spirit mark and control it.

For Rod, the only advantage is that controlling the spiritual attributes occupied by the hero Thunderbird does not increase because of its heroic status, but is the same as controlling an ordinary sixth-order undead creature.

Even so, in Rhodes' opinion at this time, the mental attributes required to control the hero Thunderbird are still extremely large in numerical terms. According to Rod's rough estimate, controlling the spiritual imprint of the hero Thunderbird must occupy at least 60 points of spiritual attributes before it can be formed.

In order to control these undead creatures, especially those high-level undead creatures, it is obviously not enough to rely on the initial spirit attributes alone, and in order to achieve this, the unique control spirit of the necromancer is required.

Through Deep Meditation, necromancers gain additional control spirit attributes that can be used to control undead creatures. The possession of the manipulative spirit attribute does not affect the necromancer's own spellcasting ability.

For those lichs who are at the same level as the hero Thunderbird, have reached the sixth rank or above, and have broken away from their human form, their control spirit attribute is at least a few hundred points. Some of the Lich High Lords in the territory of Diya can even reach thousands of points in their control spirits.

For these lichs, after a long period of accumulation, according to their abilities, they are naturally able to control the number and number of undead creatures. As for the controlling spiritual attribute occupied by a sixth-order death knight, these lichs naturally don't take it seriously.

However, for Rhodes at this time, he was simply unable to provide such a huge spiritual attribute for the spiritual imprint of the hero Thunderbird.

When the strength of the ghost dragon was improved, the spiritual attribute it occupied was also greatly improved, far from being comparable to when it had just entered the sixth order.

Coupled with the undead creatures that Rhodes originally controlled, they also occupy a lot of manipulation spirits. At this time, Rod's manipulative spirit had been completely occupied, and even the most basic spiritual attribute had fallen below 10 points.

For the current Rhodes, due to his low spiritual attributes, any spell he casts can only cause the effect of the mage apprentice level. Although Rod's mana has not been reduced in any way, Rod's current overall strength has undoubtedly decreased a lot.

Among the many spells that Rhodes mastered, the only one that was not affected by the spiritual attribute was the Titan Arrow, except for teleportation.

Due to the special effects of the Titan Arrow, from the very beginning, it was very different from the rest of the spells. Rhodes could not rely on his own mental attributes to increase the power of the Titan Arrow, but could only increase the damage of the Titan Arrow by increasing the number of artifact parts collected and putting extra mana into the spell.

As for the lack of control of mental attributes, Rhodes did not have any way to solve it in a short period of time.

Through deep meditation, necromancers are able to greatly improve their control spirit.

Unlike the improvement of spiritual attributes, which will decrease with the effect of deep meditation, and at most will only increase mental attributes by less than 10 points, but there is no such restriction in manipulating spiritual attributes.

The amount of control that a necromancer can rely on deep meditation to improve depends on the number of times the necromancer performs deep meditation.

Every time the strength of the necromancer rises to a higher level, the strength of the undead creatures that can be obtained also changes, and he will inevitably face a situation of insufficient control spirit.

When this happens, the necromancer will need to spend a longer period of time meditating in order to gain enough manipulation spirit, which is also a limit on the necromancer's speed.

But for Rhodes, it didn't take long to be able to use it in deep meditation like the rest of the necromancers.

After all, when Rhodes is in Deep Meditation, the rest of the things don't await Rhodes, and if Rhodes spends a long time in Deep Meditation, he will undoubtedly miss out on all of the campaigns in the current expansion.

For the lack of manipulative spirit, Rhodes couldn't find any good way to deal with it for a while.

Due to the special ability of the hero Thunderbird, Rod is confident that he can use the hero Thunderbird to gain a lot of experience points in the war, but in this case, Rod can only give up the transformation of the hero Thunderbird for the time being, and then think of other ways.

At this time, Rod also noticed the experience points he had.

While Rhodes was in the midst of Silvercliff City and participating in the Potions Competition, the centaur leader controlled by Rhodes was fighting for him in Vilning with the Mother of the Dead that Rhodes had bestowed.

In the process, the ghost dragon also obeyed the command of the centaur leader, and in the process of fighting, he earned a lot of experience points for Rhodes.

Rhodes noticed that he currently has a total of 141,500 experience points, which is enough to increase his level quite a bit.

"Cost 90,000 XP, 51,500 XP remaining. Class level increased from Tier 4 Necromancer level 4 to Tier 4 Necromancer level 6......"

"Get 2 free attribute points, get 2 skill points......"

After leveling up, Rhodes allocated the free attribute points he had obtained, as well as all the remaining attribute points to his spiritual attributes.

With the improvement brought by these attribute points, Rod's original spiritual attribute of less than 10 points was suddenly alleviated and recovered to the level of 13 points.

While Rhodes was assigning attributes, another change occurred in the properties panel that caught Rhodes' attention.

Rhodes found that the remaining 51,500 experience points had suddenly changed at this time.

In the Properties panel, the XP value starts to jump upwards, and after two short intervals in the jumping process, the XP finally stays at 60,900 points.

At this time, these newly added experience points are enough for Rod to continue to improve his character level, reaching the level of level 7 of a fourth-order necromancer, but what makes Rod feel concerned is the source of these experience points.

After examining the entries in the system log, Rhodes understood where the experience points were coming from.

According to the records of the system log, these newly increased experience points came from the three thunderbirds that had received the breath of the ghost dragon and the ghost dragon. Although these Thunderbirds were evacuated from the battlefield in time, at this time, under the effect of the Nether Dragon's Breath, these Thunderbirds were already dead.