DS is 4.5 and obsessed with Lego he got some last Christmas and for his birthday. All he wants for this Christmas is Lego but I'm undecided on what sets to get. He loves ninjago, nexo knights and superheroes but most of those sets are for 7/8/9+and I don't know if they would be lots more difficult to build verses the 5/6+ things I don't want to get him something he would be too fustrated with x