Jayce wins by unbalancing fights before they start.
Long Sword
Mana + AD for spam Q in canon and combo switch
Lethality + MS for poke Q canon and burst melee
Slow on Q Shock Blast canon, armor penetration
Boots of Dynamism
Stasis
Q To the Skies poke generates gold without engaging.
Q To the Skies (mode marteau) dash triggers penetration physical on impact.
Strengthens autos hybrid in mode marteau with dominate trades melee.
Scales AD with each accumulating kills assisted by his pokes longue range.
Reduces incoming damage during his phases approche in marteau.