parenting

My foster kiddo's birthday is coming up soon, and we got a REALLY good deal on a PS4 for his birthday. I'm buying him used games to go with the console. I asked him to describe what kind of games he wanted and things he liked in games. He wants a split screen co-op FPS where he's able to hunt for rare loot. He wants a looter shooter that he can play with me. Also odd criteria, but he wants games that I'm good at because it's like "watching a ninja". He explained this, and Borderlands is the only game I can think of that has all of it. He didn't mention Borderlands by name, so it's not like I'd be saying no to anything on his list specifically. I'd settle for a co-op split screen FPS we could play, but there aren't very many of those on PS4.

Here is the issue I'm running into though. On one hand, this child is turning 9. He is just too young for Borderlands. However, this child has also witnessed multiple people die of drug overdoses, watched a million rated R movies with his mom, so censoring things feels weird. Like who am I to censor some middle school grade jokes when he's into morbid things as a result of seeing death his entire life? I'm thinking maybe we just make it a game where I have to play it with him if he wants to play? Any split screen game recommendations for us that may be more age appropriate?