Heero hands down, since Kira Yamoto is too emo his Strike Freedom won't hit critical places and he tends to miss alot. If Heero was ordered to kill Kira, he will do it and has buster cannons that never miss.....
Jesus Yamato is one of the most skilled pilots any of the Gundam series' has ever seen. If this was a fight to the death, Yamato would win after a long fight because he would see that only injuring Heero would not stop him. Heero is a highly skilled pilot, and his Gundam is pretty amazing. But Jesus Yamato's skill and his Gundam are far too advanced.
I'm going to have to give this one to Heero. Though both are very skilled pilots, i think heero would pull this one out in the end. the Wing Zero, even if it isnt as advanced still kills opponents that seem out of reach. i man his buster gun destroyed a part of the Libra.
Heero hands down. If it wasn't for the technology difference Heero would win anyway. Heero can go to the extreme just to kill someone with or without purpose. I don't think Kira could even touch Heero.