https://en.wikipedia.org/wiki/Complementary_currency
There's no need for a blockchain, or distributed stuff, etc. The only thing you need is to convince people to accept it. You might as well make an app that transfers balance between rows on a database. And the reason why you never heard of complementary currency before, is that it's something done "just because you can" and has no real advantages.
I understand that none of the things I said are specific to you. But am I wrong?
The cool think about tokens is that they can be programmed to behave different ways. Can you imagine a world where each currency is programmed differently? For example, maybe one currency gets deflated with each transaction (gets multipled by 0.9), and another currency can only be sent a certain number of times before it disappears, encourage people to hold it. Can you think of use cases where that changes the utility of a complementary currency? I'm asking because I can think of a few, but it's so hard to tell whether or not they're good ideas.
The second part, outside of that, is that tokens are on a blockchain. Again, none of this is specific to us, but there are a few properties that any token gets. Namely: They are provably scarce, they can interact with smart contracts, and they can be traded for other currencies if necessary.
There's also no dependency or trust on hexel per se once the coin is created. They can disappear, but the contract/token lives on.
Definitely upside for using Ether, but comes at a price in transaction time and money.