Which card name in the set 'Journey into Nyx Hero's Path' has the highest converted mana cost.
set 'Journey into Nyx Hero's Path' refers to name = 'Journey into Nyx Hero''s Path'
SELECT T1.name FROM cards AS T1 INNER JOIN sets AS T2 ON T2.code = T1.setCode WHERE T2.name = 'Journey into Nyx Hero''s Path' ORDER BY T1.convertedManaCost DESC LIMIT 1