This is DCNU 52 Strife, this is not a fight.

Let's say Loki and Strife meets up by accident and knowing the reputation of the other, they decided to team up and cause some Anarchy.

From Both DC/Marvel Earth, which Herald can stop them.

This is a duo team. One Herald or below from each Universe. Meaning Diana and Superman can't team up, or Thor and Hulk can't team up.

Strife and Loki gets a week to cause the next World War 3. Can they do it? Or will they be stop.

No knowledge for the hero team.