Ok I'm on what seems like the last part when you fight the evil guy in..

Tip: try finding all the holo plans and go to the smugler it will be the r.y.n.o you know the lengendery wepon in all the other games. Use it on him try it it works

Or,save your big, explosive weapons for last,that way,(when he starts using desperate attacks)when his health is low, you can take big chunks out of his health at a time.

Okay in case you can't do any of the things above I will give you thde best defense and offense for Tachyon. First make sure you have Mr. Zurkon, Leech Bombs and Mega Leech Bombs and a groovitron would seroiusly help you. Second if you don't have the Trillium armor this is a great chance too get it it is the best armor in the game. Third Attain all the "missing" holo-plans and get the R.Y.N.O from the smuggler and Fourth try not to use all of your big weapons and use all of the weapons at your disposal so that when he starts his kamikaze attack it will be easy to beat him Tip don't use the leech bombs until he is almost dead Good Luck

I would simply say to save your big guns until he goes kamikaze

Listen I beat the game without the ryno this is all you need to do.You need to have the gadget death springs and alpha disrupter/cannon.Ok now just use 3 death springs and then you will go to the space place then do the alpha cannon about 8 times but first level it up to level and upgrade all the raritonium functions now shoot him 5 times then after that tachyon will shoot and hit some alpha ammo then shoot him about 4 times and he will die.Sorry for such a long message.