Pain

If Thenos would have to curse anyone he would simply have to curse his fate and his fatal bad luck to be paired against someone like Rowan who could counter most of his abilities when he was at the weakest. The moment that Rowan had determined that he would sacrifice anything to kill Thenos, then with the potential and power he had built over the years, such a statement carried great weight.

Rowan had been able to read almost all the moves that the titan was going to make and he made sure that he placed counter to all of them, and he began this battle on his terms, dictating its entire flow. He began by attacking Thenos with weapons to trick the titan into revealing a form that was geared towards fighting in melee before Rowan changed his attack pattern to range with spells.