Harkanian, Seige Expert

Whenever Harkanain, Siege Expert enters the battlefield, Target opponent creates 3 0/3 white wall tokens with defender. If this opponent attacks you
or casts a spell that targets a player or a permanent
they don't control, they sacrifice all permanents with defender.
{x},{t}: Search your library for an artifact creature or vehicle with converted mana cost of {x} or less.
Shuffle your library and place that card on
top.