The current Pokemmo OU meta game has more offensive... options... than any we have had in the past.
Trick pokemon: use one move to more or less disable the function of a pokemon on the opponents team.
Trapping: players give up recovery at times to avoid being trapped.
Life balls: are you using your balls today? A favorite is spamming growth venusaur with life ball. This also powers up already powerful pokemon such as blaziken and gyarados. The rebuttal is that it leechs your life, but that's almost irrelevant if the life ball pokemon is putting out effective and high damage output and fainting opposing pokemon.
bands: you even have bands for your special attacking pokemon now. A favorite 'strategy' is to use the special attack band then if your special attacker is being effective, keep spamming. If it's not having impact, use trick to disable the defending pokemon from stopping your attacks. Starmie is a popular pokemon that does this, but (as you know?) bands are used in combination with trick on a wide variety of pokemon.
There's also some ( 'more competive? ') offensive strats making an appearance again like the old spam spore breloom. I've even seen room for the endeavor+using speed to get some kills. As long as chansey is here, You even have a consistent low cost switch in spot. What more could you ask for offensively?
If you can't get offense going in this Pokemmo OU, then it's probably bad team building or bad timing with kingdra. You just need to make sure you are keeping up with the times (what is being used) and also take a long look at your team. Takes notes on how you lose matches. Were your loses to cancer or can your team be better?
In my case, I played about 60 rounds and took notes in my loses before I was seeing some consistency and decided my team could be better. Problems with team building are not always easy to see with RNG and uncompetitive/uncreative cancer often deciding matches. Matches where you dominate often do not give you useful data either.
As far as kingdra specifically: Kingdra is very powerful but it's ideally for mid or late game after it's counters are weakened or gone. You could call it more of a sweeper. A wall breaker is more hit and run like a blaziken or a fat ursaring. Something that can come in any time and might take something out then come back in later. You have to make sure you send in kingdra when it's the right time. I wouldn't say its best used as a breaker, it's best used as a sweeper for mid to late game clean up.
amigacho used a kingdra a lot recently. First he (she?) would scout by sending in kingdra to see what pokemon would be used to stop kingdra. The he would try to waterfall flinch you to low health then outrage for the faint. Or... take out the defender by whatever means he could. It was all about timing (and RNG) to set up a sweep. That is ( as you know?) how all sweepers work in general.