You can't loop Alexi, in NGS2 you can semi-loop him during his punch combo by resetting your guard and doing a counter (only really worked well with the BoTA)
Its Liz xD
loops been around since NG2 vanilla, when her move guard breaks you, reset your block by repushing L1/LB and she will keep looping the same move
You can loop Alma and Doku as well
^^
Doku ground pound yes , Zed ground pound dunno, chest beam yes
When he is on his knees that means he is stunned and will recover at a random time and try to grab you. Its been like that since NG2 vanilla
Master 16 solo with claws, yee