Overall this mission is pretty difficult because most of the stronger creatures (for example X-dunkleosteus) attack Icco but the weak ones (for example mantas) attack you or your tames. Icco is pretty slow and the pathway is pretty long but not as long as the path in This Little Light of Mine. The electrophorus are extremely annoying and time consuming. However, this can be made easy with the right creatures.
Use X-megalodons as they have great overall stats and a small turn radius. The X-megalodons are able drive the hostiles' attention away from Icco. X-basilosaurus can be used as they have far better stats then x-megalodons and are immune to electrophorus shock. This might be one of the best creatures to use but they have a flaw. Close to the end of the mission Icco travels into the deep, and this can disrupt the X-basilosaurus's behaviour. Backup is highly advised. The electrophorus can be used though they have the ability to shock victims this can give you or your tames more time to attack the creature and can rain terror in a pack as they will continuously shock creatures making them unable to attack the electrophorus. They have decent damage, but only use in a pack of 5+ or with another mount as one alone can't do much on any difficulty higher than gamma.