Ishamael taking it easy?

Hi Guys! I havent read the books yet, but im always a guy who likes to read around in wikis, so i think i have a general overview over where the story is going and who should be about how strong. So i am wondering about the last episode where Ishy is batteling the gang. Ishy is the strongest channeler on the dark side, male channelers are generally stronger than female channelers, Ishy has the True Power and about 3000 years more experience, so how didnt he just snuff out egwene like a candle? Shouldnt he overpower her rather easily? Logain should be of similar raw strength and he didnt even need to put an effort into tiring 3 experienced and also rather strong aes sedai? Ishy shields moiraine within half a second, lanfear performs similar in relation to siuan, you get what i mean. Even if it is somehwat cool from the shows perspective to have egwene block him, shouldnt she be unable to do that? Ishy is to my understanding the absolute best the dark side has to offer. Showing him as having trouble to overcome like the light sides 5th Strongest Channeler will kind of discount rands strength who he should be about equal to? Was he going easy or something? Because i see no reason why he should have done so at that point of time. His original plan of converting rand already failed so he wanted to kill him to have more time to prepare for his next rebirth? So why should he want to drag it out? Why not give the Signal to gentle Rand? Please help me understand :)