I find it fascinating because stretching is strengthening and strengthening is stretching, so whats the key ingredient to power?

Its to strengthen and stretch every possible fibre of muscle you can.

How can you apply this, lets say your doing a chest workout and you have a tight chest you could either do a back work to stretch out the chest and then do actual chest stretches, or you could do a chest workout and stretch the chest, or you could do a chest and back workout and stretch the chest.

The other thing you could do is stretch your spine and chest to open up the chest, but while your stretching the chest you have to be firming the rear deltoids and upper back muscles to really get your chest area in a healthy and more posturally friendly position.

So just think about how you workout and what you are working out, so do a chest and back workout with chest and back stretches

Do a leg workout where you strengthen the front of the thighs and the back of the thighs while working on the flexibility, e.g. do a squat and deadlift session with inchworms and push kicks to get every fibre of the muscle flexible and powerful

Start thinking of flexibility as a component of power as it allows you to move more muscle fibres with greater length and speed which aids in power

Another workout would be arms, skull crushers and barbell curls, with hanging stretches to stretch biceps and triceps

The workout week could look like:

day 1 chest and back workout and stretches
day 2 legs and stretches
day 3 arms and stretches

and if your an everyday exerciser you could simply repeat those days.