Fusion has aims to lead block-chain interoperability, but interoperability is not just about bringing other crypto-assets to the Fusion blockchain - true interoperability is a two-way street - which means that Fusion based assets can be brought to other chains too.
The shining example of this is ANY, the first FRC20 and the main crypto asset of AnySwap which is the gateway that makes this possible. AnySwap is taking not just ANY but also aFSN, aUSDT, aBTC and aETH onto all kind of chains, which means that they can interact directly with native assets of those blockchains and also be used in apps built on those blockchains.
On the Chain Data page you will find information on how you can connect to the various blockchains that ANY, and aFSN can exist on. To connect and bridge FSN to these networks connect with MetaMask or Ledger to the AnySwap Bridge and choose the network you want to move ANY or FSN onto. If you want to bring back FSN or ANY to Fusion you would instead choose the redeem option on the bridge, while connected to the network the ANY or aFSN is currently on.
In the case of aETH and aUSDT and many other aTokens their native network is Ethereum, so here the option is instead to bridge them to Fusion while connected to Fusion.