I do use VH. if you don't that's your issue. you need to learn to determine for yourself whether you feel an event unit is worth getting or not. checking out wikis (there are many players using google translate to manage roughly) for the data and consulting veterans on why and how an event unit is worth getting and state your thoughts on it to see if it is erroneous, otherwise you won't improve.

lumaria at mincost costs 14, same as a full cost Khuri/Free (silver VH), with almost the same attack, but with +7% VH attack AW passive which is excellent for VH use.