Blitzwing, Cruel Tormentor // Blitzwing, Adaptive Assailant

After Blitzwing, Adaptive Assailant converts into Blitzwing, Cruel Tormentor, it's still an attacking creature in combat. It will still have any gained abilities, including the ability it gained at the beginning of combat. Notably, if it has somehow gained double strike, it will convert before dealing combat damage in the regular combat damage step.

The cost is an alternative cost, so it can't be combined with any other alternative costs. It can be combined with any applicable additional costs.

Similarly, an ability of another card that instructs you to "transform" one of these cards will cause you to convert it, even if that ability doesn't use the word "convert."