It's more about the 'treachery' than the 'old age'...

"So, BOY you think you have what it takes to drum ME out of the colony?" The General demands in his aged and cracked but still powerfully and deep voice.

"Actually I DO you tyrannical treasonous wretch!" You shout back, eyes alight at finally coming face to face with your father's murderer.

"Then Draw STEEL you arrogant pissweed!" The General snarls and pulls a clamor out of a sheath on his back.

Holding the massive sword that you could probably barely lift in the mits of his gorilla like armored exoskeleton The General charges you, but you have one more trump in your hand. "Clapuchan: Zulu Alpha X-ray!" you shout and dive out of the way. The Genreal's sword slices the air where you would have been had you not moved, but his reversal never connects with you, as his armor seizes up and ceases to obey his commands. Muffled curse words and invective come out of the armor's helm but the speakers are off line too so you cannot understand what he is saying, nor do you care. Moving up behind him you take out an Allan Wrench and open a panel on his back which reveals a tiny keypad. Using the tip of your knife you type in a five digit code and all of the armors joint seals come apart, but The General, weak from old age and sickness still cannot move, pined by the weight of his own armor.

You wrestle his helmet off and put your pistol to he back of his head. "I found Major Connors' hummer." You whisper in his ear. "You betrayed your brothers in the United States Marine Corps, and every oath you swore to uphold, and for that alone you deserve to die."

Then, much louder, you shout for the gathered crowd to hear: "Sic Semper Tyrannous!" And pull the trigger.