Oh the Rekka CW lock down is simple. to perform this you execute a CW, what matters here is the strength of the CW. For example if you do the Short CW, you will end up close but push back because of the block stun, performing a rekka will leave you open for a counter attack which isn’t worth it. Perfmroing the foward and RH rekka’s allow you to do standing fierces safely but they come with a window of opportunity of being countered.
RH CW- Quick, and when opponent is cornered it hits for twice depending on the hitbox of the character. Their is an open window to counter fei, it begins right after the second hit from the CW, at this point you can be countered accordingly if you do not recognize the timeing of the Fierce. It’s really simple and done like this.
Opponent in corner- RH CW, First hit blocked, Second hit blocked, Fei long whiffs the third hit, and at this moment is when you want to input the fierce punch. It is at these frames when Fei will land on the ground and is vulnerable to attack, it’s not a good idea to do a rekka since the startup is slow and is easily deviated.
Opponent in corner- Foward CH- All hits of the Chicken Wing connect, the third counts as the overhead, this is simple since reading the third hit gives you a great sense of intuition of hitting fierce. After fei lands you can simply end this chain with standing jab, and short flame kick, or standing jab jab to allow push back and fierce rekka, strong rekka, strong rekka. Or option three, you can simply sweep to counter a throw. Here is a huge window for fei to do some variations of offensive/defensive attacks. after the foward CW is blocked, you can do crouching jab, into standing Fierce and execute rekka, tick throw, defensive sweep to counter a throw or simply block to counter any AA with a fierce rekka chain.