Complex sentence: Nightcrawler and Colossus travel to Mariko's grave, where they take out Wolverine's sword and slam it into the grave as a sign of them being together, but the men guarding the grave take it as an insult and then they attack them.
Split into simpler sentences: Nightcrawler and Colossus travel to Mariko's grave, where they take out Wolverine's sword and slam it into the grave as a sign of them being together. The men guarding the grave take it as an insult and attack them.