rioty

Elusive mercs/poison main here, I am not a terribly experienced player but if nothing else I can probably share some of my habits as a /poison MM. It's definitely a weird powerset to objectively rank the team contribution of, so I'm mostly basing this on the most common refrain of parties I join, "wow, that went unusually fast", sometimes followed by "yeah, we have big debuffs". Mind you, I have built as a -def and -res machine first and foremost, with even my mercs helping in that role. This is naturally more useful against tough enemies that last longer than five seconds to begin with, so don't sweat it if you're not adding much to a +0 speedrun. The combination of fickle MM pets and debuff-based support naturally struggles to keep up in easy content but becomes exponentially more useful when it actually matters, so how much mileage and enjoyment you get out of it depends on what kind of content you plan to run. I find that I end up having two somewhat different roles in a good group, depending on the difficulty of the content and power level of the party. If it's anything resembling a speedrun and other people are steamrolling the mobs, I go all in on support and just stack debuffs, prioritizing -def and -res. You can be deceptively useful to speedruns because of your ability to make enemies melt even faster, so lean on it, hard. If your pets catch up and get some hits in, that's great, but if people are doing that much damage then your envenom is also doing proportionally more for the team, and with poison trap and neurotoxic breath loaded with procs I can still contribute a bit of personal DPS on big packs. Don't be self-conscious about your pets being a drag in speedruns, it's just an MM thing and people know that, focus on support. They'll be there for the big bosses. Your job is primarily to be among the first at the next enemy pack and hitting them with the envenom > weaken combo ASAP. If it's more difficult content going at a moderate pace so your pets can keep up, stack debuffs as soon as the tank has pulled and sic your pets on the highest rank enemy available. You want to burst down bosses, lieutenants and priority targets so focus fire, leave the random minions to the AoE fiends who will be clearing them out pretty quick with envenom up on a nearby boss. Alternatively if all your debuffs end up drawing aggro, don't be shy about leaving your pets on defensive and just wading into the fray so you can help soak some damage. This is the kind of content where you really get to shine as a well-rounded debuffer that can neuter enemy packs into oblivion while helping your team keep up the pace. I really encourage upping the difficulty a bit as /poison for this reason, not because it's that good of a set in the grand scheme of things but because your ability to be a force multiplier hinges on fighting enemies worth debuffing, and you'll feel that much more impactful.