Dr. Doppler

Dr. Doppler was the first Reploid scientist. Early in the story of Mega Man X3 he claimed to have created a vaccine to the Maverick virus, and he also created Dopplertown. Unfortunately, it soon turned out that the "vaccine" was a placebo, and Mavericks started to pop up everywhere. Later on in battle, it is revealed that Sigma took control of Dr. Doppler and forced him to create a new battle body for him. Dr. Doppler's fate depends on whether or not Zero is still active. If Zero is still active, he comes into to take out the Sigma virus in the end. But if Zero had to go back for repairs, Dr. Doppler makes one last move and self-destructs, taking Sigma down with him.