Originally Posted by
lolix
Well , generally lafate says in the guide for each event if a unit is worth getting or not , but other then that .....well , a lot depends on what units you have. You could make a thread with your units if you want some advice. Between lafate , charles , sora and tenhou , and sometimes myself , there are a lot of people that could offer some advice. Tha being said , as a rule of thumb , look for the most general use units , that don't have some very easy to get replacements. For example , this curent events has a platinum ninja. Seeing s u can get a way better ninja in saki....which even has the same skill ( so u can even try to max skill saki). That means there is no point in getting this event unit or try to min cost her , unless you're a perfectionist.
Same goes for the events that drop archers. Between a spica that is easy to get and a free bashira , there isn't much of a need for 3 archer , except for some possible weird instances.
Right now there is not much else to say.