Um, no. The pokeradar can only be used in short grass and it is for chaining MULTIPLE pokemon. If you are asking about weather you can get shiny cresselia/mespirit you will have to soft reset for them.
Chat with our AI personalities
Yes, it does it causes cresselia and mespirit to not run away for a few turns.
Yes, you can, but it is confusing, not knowing which is which. It is easier catching Mespirit then attempting to catch Cresselia
Dialga, Giratina, Heatran, Mespirit, Uxie, Azelf, Regigigas, Rotom, Cresselia,
It will keep fleeing unless you have a Pokemon with Mean Look or something like that so it won't escape. Try catching a wild Golbat. The same is for Mespirit.
I thinck quick balls they work the best