Hi & welcome! Yep, I was just about to suggest the squirt bottle too when I read Ali's last post. I would definitely use it when you catch Indiana chasing Lucky. You may also notice a particular look on his face or posture when he's about to take chase. If so, you can give him a squirt just as he starts to takes off. That should take some of the fun out of it. Hopefully, the kitty will also put him in his place soon, too. If you've been clipping Lucky's claws, I would stop now and let him get fully armed, too.
Neither Cara, Halley, Daisy or Sam ever showed or shows any interest in the kitties except to snuggle with them. However, Cassie has occasionally chased them a little. We have 2 house cats & if they get into a cat tiff, Cassie likes to break up the cat fight & then chase one of them to the other end of the house.
I have mostly trained her out of it now by just giving a loud, firm "NO, kitty!" when she does it. However, she turned 3 y/o in May so she's much, much older than your little babe. Hopefully in time, Indiana's guardian Pyr instincts will kick in and he'll decide to snuggle & protect the kitty and will give up this chasing nonsense.
LOL In the meantime, the squirt bottle should give him pause though (or is that, "paws"). Ha, ha!
Again, welcome to BPO!