depends...
well for starters no template at all, as in not even the kaiser, will take days, for the simple reason that you don't have anything to compare with
it will just about 95% end up as crap that can't be used cause it doesn't fit
now, recoloring an existing sprite (any non kaiser) should take 30-40 minutes in p.shop or 2 hours in paint, and that depends on what color detailing you put and if you'll add stuff
lastly a kaiser made thing , which you gonna draw everything for also splits to 2:
a. original, will take a day or 2 depending on work hours a day, up to even 8
b. copycat, as in you got a kaiser but you are thinking of other sprite as you make it so it ends up looking like a combination of a sprite or 2 which takes about half the time since you already know how it looks..
take or add 3-4 hours to each judging by the skills of the maker