Complex sentence: If the user adds a torrent from i2p, it will be seeded on both i2p and the clearnet, and if a user adds a torrent from the clearnet, it will be seeded on both the clearnet and i2p.
Split into simpler sentences: If the user adds a torrent initially made for I2P, it will be seeded on both I2P and the clearnet. If a user adds a torrent from the clearnet, it will be seeded on both the clearnet and I2P.