I've noticed that pretty much everyone has use duplicate Gold servants to lvl np and I know that's how DW want you to play. But I want to know if it is viable to ascend and lvl up skill for duplicate servants to use on your own team.
For example, if I got two Memelins but I don't have a Jalter, would it be more useful to lvl both Merlins and their 3rd skill and just use a support Jalter?
You can't use 2 of the same servants in a party, therefore it's useless to level an extra copy of the same servant. By doing np2+ you make your servant's NP more stronger/effective.
EDIT: I should mention that this doesn't include supports. You could have 2 of the same servants only if you use a support who has the same one. So for example, your Herc + support Herc is possible but you can't use 2 of your own Herc's.
It's better to use to upgrade the NP because you can't have more than 1 copy of the same servant in your lineup except if it comes as a support from a friend.
If it could work I could use 3 Merlins, two in front and then swap it out using Combat gear for the third Merlin. But it looks like DW thought of that and made sure it wouldn't happen
