On Pokemon Platinum, to get a Pokemon that knows a 1 hit KO move and lock on or other move like that?
Smeargles your best bet. Then Articuno because it learns sheer cold at like level 78 and you can give it mind reader by giving the heart scale to that guy who makes your pokemon remember moves!!
Yes, it can... But, only 2 pokemon that could learn it... They are Articuno (Sheer Cold and Mind Reader) and Smeargle (any 1HKO move and any lock type move).