Just some few days to the nikah d brother is having frequent erotic dreams of his wife to b soon.Wat advice do u have for this brother. Is it a bad thing?.

Assalam Brother , I can not imagine why anybody would think of this as a bad omen , This just signifies his craving for heer which is perfectly normal.

Not every body sees it d way u see it bro.some will say why must u make love with her in d dream? thus she is evil.so u see my brother

Except you are actually looking for something evil about it.
I think its just fantasy on the dreamers part
Meanwhile thinking about something frequently can follow you to your dreams.
If you are worried follow proper ethics before sleeping by doing wudu,laying on your right side, doing the recommended adhkar sha !
It will help

^^^Wudhu actually helps, I can confirm. I only have good dreams the nights I do Wudhu.