Outwit. Outplay. Outlast
What's your strategy for the poison ruleset? Mine that works quite well till the Silver leagues at least is to simply outlast my opponent.
This is a battle with no legendaries and as you can see, I have my two favorite self-healing monsters for this ruleset: The Sea Monster and The Water Elemental.
My opponent had double healing on the Shieldbearer which ordinarily would work quite well but after three rounds of poison, the healers have died.
Meanwhile, my strategy as you can see was to simply last as long with the self-healers at the back and then once my opponent's monsters had died off or are dying, bring them into play.
This strategy isn't guaranteed a win. If you were to face another self-hear with a scarred llama summoner and its last stand, this will lose. Also, if you have monsters with immunity like Kralus, you could overcome it as well.
But for the most part, I like this really cheap strategy and the Sea Monster goes for very cheap in the rental market. It should be worth more because of its usefulness in the poison ruleset which is fairly common.