Complex sentence: He would appear for one final time before a defeated Galvatron, his spirit reaching out across the dimensions to encourage him to fight on-leading Galvatron to his final demise at the hands of Optimus Prime.
Split into simpler sentences: He would appear for one final time before a defeated Galvatron, his spirit reaching out across the dimensions to encourage him to fight on. This, ironically, led Galvatron to his demise at the hands of Optimus Prime.