Shadowslash wanted to reunite with his family once more but because of the distance between the Defender Island and the Thousand Forest Continent, it would take months for his group and that was even after implementing methods to increase their speed.
But he wasn't worried, besides he has another kingdom that is much closer to this place, as long as he could establish a connection to this place and to his kingdom, then the amount of time needed to travel fro and back would decrease greatly.
The closest kingdom he owns between this place is the Beast Continent, with the bugs as his messenger, his two friends, Fire Demon Dragon King and Old man emerald.
LS is also present near the vicinity of the continent and judging from the quality of his bloodline and his rapid Growth, he would definitely be able to help him in the upcoming war.