captainwolfos wrote: »I think there's one that gives a small damage bonus for a few seconds, but otherwise they're purely cosmetic.
There's also one people used to use in PVP as a sort of beacon, showing where the zerg needs to go, because it created a huge vertical beam of light that's easy to spot, but as far as I'm aware, mementos no longer work in Cyrodiil.
TL;DR: no, they're functionally useless, but they're there to collect if you want them.