There should also be rewards for failure in the pvp competition.winner gets 2 pvp coins and loser get 1 pvp coins.Each pvp game needs to last 5 minutes or more to avoid brushing coins.

I believe this policy will attract more people to pvp and make the game more interesting.

However, giving rewards for people losing pvp matches could mean they would just exploit it or intentionally lose them nonstop to get rewards. Ranked PVP ladder would get filled with people who would care 0 about winning and would just exploit it for rewards. They could use legit teams but spam stupid moves and choices vs your pokemon to lose on purpose (spamming non-effective moves, setting up on something that makes no sense, etc). There's a lot of ways to exploit giving rewards to people who lose, even with time constraints or limits to prevent instantly losing.

Yea it will break the system... it would encourage people to loose on purpose rather than improving themselves and get better at it so that they can have a better chance to win.

I suggest a reward at the end of the season. For those who reached 50 pts, 10 pvp coins, for those who reached 100, 20, and like that. That will encourage winning. Of course, this will add up to what you recieve if you end up in top 25 ladder.