Reina can actually option select her own string using her b1+3 parry. You can use HW 1 to either punish the single hit or CH the heat extension. It's reactable and very consistent against other Reinas.
Other notable parries are df1,2 (launch), HW 1,4(launch) and she can parry both sen 3 and sen 2 for a heat engager punish making it a very useful response to ff2.
