See Artifact Person. This would share the same plane with Overclock. It's me hoping to finish Rhondite War. The ability is random. Chain is the instant or sorcery does something extra if you have another spell on the stack. Unsure of wording to make that clear and work.

The individual ability of this Chain, this card ignoring hexproof, is just what popped into my head to example. If that specific thing doesn't work, just mention it, but it's something I'm actually interested in fixing. Again, the ability is only there to show that Chain gives a bonus. All instants and sorceries with Chain would have different bonuses of course.

As long as what owns another spell? Do you mean "as long as you control another spell," i.e. you have another spell on the stack?

Also, ability words can't have rules functionality, so "Chain" shouldn't be italicized

Yeah, I missed "you" in the reminder text. It's basically "if you have another spell on the stack" except we can't say stack. Does it break the rule to imply the stack exists or is only the word itself taboo?

I think this is fine. My main quibble is that it should say "you control," not "you own," because you control spells on the stack