Complex sentence: He appears to be friends with Tessen, Tetsuhito Kagiroi and Mataza, his attitude toward the loss of Tessen's abilities to Souichiro, sours his relationship with the newly crazed Tessen however.
Split into simpler sentences: He appears to be friends with Tessen, Tetsuhito Kagiroi and Mataza. His attitude toward the loss of Tessen's abilities to Souichiro, sours his relationship with the newly crazed Tessen however.