So today I was in a duel then the ranking system dueled me with a knight rank while I am below 300 ranking the knight one had power pips flowing every round and he had judgement and atleast about 60 power pip(didn't check but was lots of power pips coming in)the health was very below mine I am assuming a level 25 then I fought a private with lots of power pip chance but more health than mine then once I fought a person with really high ranked spells while I was about 20-30th level like ranked 7+ than a person who I won aggensed I got 2 arena tickets(not aurging how it gives but) once I lost to a private and the private gotten over 14 tickets.I am even using crown gear with card and Meowiatrys healing amulet with satyr but still always getting beat up in my 2nd age (now) I have over 10 losses and only 2 wins.I am really looking forward to level 58 for Judgement pet I am now 44
In my opinion, the best levels to use in PvP are Levels 20-25, and whatever the max possible level is.
At 20-25, any high ranking opponents you face will have an extreme health disadvantage; you also only occasionally go up against high level opponents like Master and Grandmaster, and you can usually beat them with strategy.
At max level, no one can beat you with a level advantage anymore--all max levels have access to the same equipment and abilities, so it's a level playing field.
However, at other level ranges, I find that you become much more vulnerable to getting matched badly--opponents start having gear and abilities that you don't have, or can't adequately defend against.