The second target needs to be within 5 ft. of the first. If they're flanking you then they're 10ft apart. So no, you cannot cleave to hit both. I considered a long time to just allow it, this is what would have happened if I did [1d20+7=20] you would have removed both of them from the equation, but I can't allow it this time. We can consider if we want cleave to be more versatile in the future.
Cat swings at Mr. Bigglesworth.[1d20+7=13 vs DC13 (boosted+1)]and hits. He didn't stand a chance and puffs away in a purple cloud.
"Alright, looks like we don't have any other options Mrs. Bigglesworth, hold her down, we're coming!"
Ashley casts Summon Mechathereal Lynx. With a loud crack Helena is back from the negative plane and Ashley crouches, her cloths fall away, she kicks off her panties and mamillare and they both race toward Cat.
Mrs. Bigglesworth moves around cat and attacks with her claws.[1d20+4=24 critical hit!][CON 1d20+3=5 vs DC14]Mrs. Bigglesworth hit for [(1d4+2)x2=10 magic slashing damage]Cat has one level of exhaustion, and a open gash on her[1d20=12 1d2=2]left elbow. She will now have disadvantage on ability checks due to the exhaustion.''
Helena rushes and finds herself with half cover behind a potted plant within striking distance of Cat. Ashley panther races across the field and is in full cover in some trees just south of Cat.
That's the magic of Bear system luck, sorry Cat. Cat is down to 6HP and surrounded by three fully healthy cats. At this point lasting 6 or 7 rounds will just gain you slightly more AP share. You may surrender at any time or simply disengage with your ring of obscuring and jump off the map. There's still a chance you will win, but you'd have to have a lot of rolls in your favor from here on out, you could use the ring of obscuring to escape and kite them as well while firing arrows.