What you want to do to farm minions is get a vampiric scepter right away and keep your rage full for criticals.

You can vary the rageblade for something else if needed, and or get the last whisper instead of the infinity edge. Nashor's tooth for replacement is the best.

This is my favorite part; you can solo baron at the end once you have a full build, also you want to get blue for cooldowns and red for speed reduction and burn damage (against enemies), and you want to make sure you can get as many minions hit in your spin for rage, plus keep your rage up for critical chance so then you heal more each hit.

he can have at maximum about 500 ad with all the best possible buffs
Cho'gath has one-hundred-twenty-nine natural attack damage and with his vorpal spikes he can do about two-hundred natural damage, but, tryndamere has the passive to get more critical strike when he has more rage, doesn't use anything costwise, and is indestructible to all but the spawn turret with 'undying rage'. so don't get dragged in to the spawning pool. Use W while an enemy is either attacking you (so they do less damage to you), running away from you (for slow), and also for both. Have flash for escape and