How do I make an object rotate infinitly?

I’m implementing various weapons into my game which includes ninja stars but I have a couple of problems on the animation

How do I make a weapon constantly rotating without the use of animation frames?

And how do I change an object’s opacity then turning it back to its original one after a few seconds or if a condition is met?

The rotation action without condition is constantly rotating

With a timer or the Wait action.

Thanks alot, I tried this out and it works!

lastly I just want to put this out on this thread so I can avoid creating another one
But I have a shotgun weapon and its working as intended except for the pellets, currently enemies will only take damage from 1 single pellet, my shotgun has 3 multishots and has the fire bullet behavior but even if the enemy gets hit with all 3 the enemy will only take damage once, like for example the pellet does 1 damage and the enemy gets hit by all 3, technically the enemy should take 3 damage but currently the enemy only takes 1 damage regardes if all 3 hit it.