Simplify the following text for a Grade 5 native English-speaking person.
Original: Grover is the best friend of Percy Jackson , with whom he has an `` empathy link '' , allowing them to share emotions , but also means if one of the two dies , the other will probably die , too ( or that they will be left in a permanently vegetative state ) .
Simplified: Grover is the best friend of Percy Jackson . He has an empathy link with him .