けれども、彼は

but he

→ けれども
phrase Rare #37,684
but he けれども means “but” or “although” and is somewhat more formal than けど. 彼は means “he” as the topic; the phrase commonly introduces a contrast involving him.
JA: 彼は忙しかったけれども、彼は手伝ってくれた。
EN: He was busy, but he helped me.

欠点はあるけれども、彼はいい奴だ

Although he has his faults, he's a good guy.

私は彼にドアを開けないように言ったけれども、彼は開けた

I told him not to open the door, but he opened it anyway.

理論は理にかなっていたけれども、彼は納得しなかった

Although the theory was logical, he wasn't convinced.

何度も失敗したけれども、彼は決してその計画をあきらめなかった

Although he failed many times, he never gave up on the plan.