We used to be able to use them. Disabled quite a time ago.
Veit ég aðég hékk vindga meiði á nætr allar níu, geiri undaðr og gefinn Oðni, sjálfr sjálfum mér, á þeim meiði er manngi veit hvers hann af rótum rennr.
We used to be able to use them. Disabled quite a time ago.
I remember when the players escorting a scroll would all activate the memento that spawns a blue pillar of light (Finvir’s Trinket, I think) as a way to confuse pursuers.
There’s another memento, the Fetish of Anger, that gives a temporary damage bonus, which probably isn’t a good idea in Cyrodiil.
While mementos can be fun, I think ZOS did the right thing by disabling them in Cyrodiil. The potential for trolling, griefing and exploiting is probably not worth it.