Note: All though these combos are not used on an evasion dummy you can still do a combo like this to your opponents. Edit: Okay yeah I literally just found a combo that still one shots even if they evade expect that video soon like exactly 10 minutes after this message
If you mean stun grenade then It's not completely true. Stun grenade slows and slightly blinds your opponents so there's a chance that they can block or counter but I don't know yet I'll have to find out
They can act during stun grenade but you can still go for an m1 while they're slowed and bait out their counters, or you could just use your 1 or another moves like ult