Monkey D Luffy - can moves and strikes lightning fast~ he can strikes multiple times to multiple angles in an instants!
Natsu Dragneel - can using more destructives fire elements, even though he can't strike like luffy does but his fire is more powerful so far.
what's up so far -
luffy has gained the power of HAKI!!
which he can now predict enemy's thoughts and movements, enhance his strikes and defence at will, easy up the pressure of GEAR 2ND, and even overcomes enemy's will!!!
natsu has gained luxus's lightning, so he can use both fires and lightning!