No love for the Hellcat/Sekhma duo? Works with many things, but heres my favorite for general use:
Mercy fills hellcat, or A1 fills on a red or blue match. Convert accordingly, try to avoid yellow > red, but hit blue or brown to red if you have to, especially if you see it will drop your next converter cast into alignment. Save Mercy if they have a Bone Dragon, or if they have a Mab/Sylvanimora and it looks like you can't reliably do the full chain. You can also target them out with a couple Sekhma casts. Can't take many hits while you are getting set up, but usually doesn't take that long to set up, either. When used correctly, a short spell chain is all it takes to wipe the opposing team from existence.
This one takes some foresight and careful use of spell, but is capable of using chain AoE spells to wipe the enemy team without dropping the turn on the second turn. Despite the name, you want to avoid converting red to yellow for as long as you can, because any cascade match (now even match 4s) on red has potential to refill Alchemist so you convert other stuff to yellow to keep the chain going.
(Switch krystenax with Mercy for a more reliable loop start but potentially longer battle)
If you just want some brainless fun (and happen to have a bunch of fully traited mythics lying around), this is something different:
Marilith is often spammable back and forth with Aby with cascades and random matches lowering your opponents attack. Abynissia is backup mana engine and gets infernal king out if Marilith does happen to die. Famine sandwiched in there quickly gets his mana up, preventing the great majority of spells. Don't take it versus another Famine, though, the team slows way down if Marilith's magic gets lowered by a bunch and is hard to sacrifice if you have withered the enemy's attack by too much.
Looking through my teams, I now realize most the slots are Guild Wars style teams.. that I end up using in normal PvP sometimes for a chance of pace because I need something else in GW to counter an event boost or specific. I could probably tweak a few of them to not be so unwieldy or defensive for general use. Also trying trying not to retread any of the main core of other teams that were already shared.