Although he usually read extensively and had collected quite a few methods and materials concerning beast taming,
truly advanced methods were often secrets never passed beyond the inner circle. Unless taught personally, outsiders found them difficult to obtain.
Su Shi'er naturally understood this perfectly well.
Thus, the moment he made his move, Spirit Contract, Blood Contract, and Soul Contract all took shape at once.
It did not matter if things were more troublesome and time-consuming now. If the Thunder Spirit lost control in the future, that would be the greatest trouble.
Immortal Essence slowly flowed out from Su Shi'er's body, while he already held a Spirit Crystal in his palm to replenish the Immortal Essence being consumed.
A full two hours passed. The Immortal Essence pouring into the contract pattern before him had already reached nearly fifty or sixty percent of Su Shi'er's peak reserves.
The pattern, which had originally appeared somewhat insubstantial and drifting, shrank to the size of a fingernail and became incomparably solid.
"Go!"
Su Shi'er suddenly roused himself and shouted sharply.
"Whoosh!"
The painstakingly condensed beast-taming contract pattern shot through the air, striking the Thunder Spirit ahead in an instant and entering through its head before vanishing.
The next moment, the Thunder Spirit, which had been completely motionless like an inanimate object, suddenly straightened all four legs as its body convulsed violently.
Even with muddled, chaotic intelligence, a living creature instinctively resisted and rejected being enslaved.
Unfortunately, the Thunder Spirit was clearly still rather weak. Moreover, the power within the Divine Thunder Source inside its body was vast and impossible to refine.
It was like a small snake that had swallowed some enormous thing, unable to digest it quickly and thus temporarily incapable of moving.
Though the Thunder Spirit resisted instinctively, as the power of the