Do I understand Yuri wrong?

So lemme get this straight. Ally counters-Gets Yuri Funny buff-uses buff when shield pops-yuri gets 1 out of 6 counter stacks-yuri gets to 6- Yuri goes boom.

Right?

But my team is using skills and countering and all that and she wasn't getting points. Something bugged or was it maybe something I misunderstood?