If there are no poison immunites on the opposing team, using Gimlet Stonebrew instead of Leprechaun and a maxed or near maxed Titan class is probably optimal. A single-3 alignment stonebrew is often enough to get you started, and a 4 alignment stonebrew often gets you a turn 1 scrop cast due to starting with a duststorm and passive explosions. You can do the same thing slightly less “safely” with Dervish (I still take lightning strike over dodge running this, it helps the flow a lot), or toss Gimlet in front and hazard slightly less optimal classes.
You can deal with most (eg., not also stun immune, ie dwarf) poison immunites with the Essence of Evil variant, including entire kingdoms worth if you replace your accelerator with Obsidius, eg., EoE/Webby/Scorp/Obsidious or EoE/Scorp/Obsid/Eury at the cost of some speed, but it still outpaces 40 some-odd irongut setups for me due to consistency. Although you will drop your green storm usually around the time you get your first kill, you generally want the brown mana at that point to finish the fight.
Gobtruffle setups seem to be the most consistently decent speed, but no matter which one I use, I can’t seem to push them under what tesla/rowanne setups are capable of, although gobtruffle tends to be safer. I’ve tried a ton of variants (doomed glaive/TMQ variant, qilin without an empowered accelerator, using dervish with my key variant to close battles more quickly) - every time I trade setup speed for closing power, it seems to roughly break even. Maybe with a maxed dervish and some magic medals it will pull ahead a bit, but with that kind of setup cost, I think I perfer all things Scorpy or Irongut. My low levels will probably stick to truffling for explore 12.
Didn’t have a whole lot of luck with Ubaset based stuff. Shame he was nerfed so much, most setups have him fall just short of a lethal hit even on a softened target first cast, which means you need like 5 drop turn casts to close a match. This one was okay:
I wouldn’t call it “slow”, but it isn’t exactly “safe” either, as switching to a non-dervish class or taking off lightning strike for dodge slows it considerably, and you can die to a easily couple skull skyfalls, even though it is rare. Doesn’t generally care about any immunites except instakill immunity, though, and even that can be plowed through with massive damage. Switching gimlet and hero might help for some kingdoms, like when they have a stun troop up front or when the hero is in danger of getting one-shot during setup… but enraged attack boosted hunters marked skulls do a lot of damage.