Patch, coulson, quicksilver for me too, didn’t have any troubles and match wasn’t all that long, maybe 5 minutes. Scl7. I dunno, he used to be much harder for me to beat when he crushed your team in a dozen or so turns.
If you have Black Suit Spiderman with a decent # of purple covers (level is irrelevant), he makes the fight way, way easier. His match damage is still non-negligible, but you don’t get the “soft enrage” effect when he throws out 7 strikes in unmatchable places in a row.
3* Wolverine
3* Quicksilver
4* Medusa
Wolverine generates the strike tiles, if need be you can destroy them, which enables Medusa’s team healing. In addition, you have his healing power.
Medusa can shake the board (Hair Meddle) and keep your team alive with generating health (Wolverine factors in here).
Quicksilver provides his tile swiping (black).
My old stand-by of OML + Coulson + Quicksilver did the trick.
Still, why the secret buff to this boss with no mention of it, and no reason why he changed?
The previous run was a good enough challenge, even though mine was stupid over scaled at max level. Thanks to Shield Ranking determining scaling, mine is “only” Level 330.
The secrecy is almost more irritating than him being harder. Did they think no one would notice?
Got it finally with Coulson, Switch and KK. Thanks for the help all.
I beat him with Coulson, Carnage and Medusa
tried most teams I read here.
its always the same - I run out of enemy strikes to match and lose because of match damage alone.
in the other hand, its just 3.5k iso, and way more annoying than ddq.
keep kaecilius the way he is, don’t see any negative in a break every once in a while.
Hanlon’s razor would seem to apply, “never attribute to malice that which can be explained by stupidity” 
Patch, Coulson and MrFantastic, u have lots of moving titles and some defensive as well and patches can put out some more to finish quickly the fight
Ive beaten him twice now with 2 different teams:
Coulson - Invicible Woman - Scarlet Witch
&
Coulson - Spider Woman - Medusa
It aint easy since i play in SCL 8 and im an 3-4* transitioner but with some luck and planning my matches i have been able to beat him. Had i know he was this hard i wouldnt have choosen SCL 8 tho.
Eventually got it with a 3* Team of Patch, Hulk and KK. The board looked like Earth Day it was so green! Finished with maybe 1K left on KK.
Enemy strike tiles that you create should still hurt him.
Champing Electra just for this guy is almost worth it. Patch works well with her. Normally I like to team them with MaxPun but Mr. Fantastic or Quicksilver are the obvious fill-ins here.
War-Machine (the meatshield, build is irrelevant, tanks all his colours, boosted to 371 he’s sitting on ~34k health), Mr F (5/5/3 - use Blue to take the strikes out and minimise damage), Coulson (x/5/x - use Purple in exact same way as Mr F’s blue). I’m currently 2 for 2 on Kaecilius with no wipes with this team.
I use 5* BSSM, 3* Hulk, and Patch. Patch makes strike tiles to match while hulk makes green. BSSM acts as a tank and reduces the enemy strike tiles.
I used Medusa, Mr Fantastic, and Quicksilver and got it first try, but it was a really long match. Next I’ll try your team.
There’s a wording issue here. YOUR own personal strike tiles don’t add any damage, and matching your own doesn’t hurt him. However the purple strikes given to Kaecilius from Berserker Rage do technically count as his, and would thus damage him if matched. That’s why you’ll see Elektra in a lot of these teams as well, the purple strikes she gives to the enemy can be used to hurt Kaecilius in this case if you match them. The ones you steal and strengthen don’t help you, but the free 3 ones you give him will cause him damage if matched.
I did it with 3R&G, Patch & 5 Hulk (for the bonus matches per turn and “additional health”). It’s not a reliable team, but it worked for day 1.
Elektra (4*), Medusa, Scarlet Witch.
SWitch makes purple. Elektra takes his strong tiles (which helps keep you alive) and gives him crappy weaker tiles. Those tiles are on purple, so SWitch has better chances of matching them with her passive. SWitch’s green lets you carve up the board to hunt down some purple AP if you need it for Elektra, or maybe try to cause tiles to fall so you can match other strikes (it’s inelegant, but something to do with green AP).
Elektra’s other powers are unnecessary utility. You can steal some AP with her red, and her black can absorb damage, but neither are necessary.
Medusa sits back and generates AP when you match enemy tiles, and health when you match friendly tiles (and matching her countdown obviously gives more of those).
Ran this team in SCL8, maybe I just had a good board, but I almost didn’t need Medusa. It took longer than past versions of Kaecilius, but it was easy street.
I had trouble with this yesterday with 4* teams until in desperation I went back to the old 3* standby of Patch/Kamala/Loki.
Loki purple for shake and black when K gets too many unreachable tiles on the board (and the shields help as well), KK for heal and green generation (although most Purple will be spent on Loki), and Patch green generates tasty purple and red enemy strike tiles (and self-heal). Worked fine, although I’ll give a couple of the 4* teams another try today.