What is your favorite tekken character

I love Yoshi, but I don't know how to use him because whenever I do manji kicks or stone fists he ends up going dizzy and falling. Can someone explain what is the suicide and fake suicide attacks for? what is the purpose of giving the opponent life? Yoshi's cool, but I don't get why he does moves like that. Yoshi in Tekken 5 has the best costum, but as for weapon Tekken 3.

P.S. Please explain the purpose this is confusing me big time