Vinyara cannot reliably remove buffs and reduce energy, even though she should be able to.

[bronze gust]

In Grave of Curse, an accuracy of 300 is recommended at level 20. Vinyara has an accuracy of 365, and her ultimate ability states, “dispelling all their buffs and reducing their Ultimate Energy by 100%.” In reality, she only manages to do this 85% of the time. Sometimes one of two buffs remains, and then the energy is not reduced. This makes timing impossible.
In addition, Xenos can reset energy even though this is not mentioned in his skill descriptions. I can see how the energy bar for the heroes goes down a little bit every now and then. It's not much, but it can completely ruin the timing.

[river hound]

theres always 3% chance of missing even if your accuracy is recommended or higher

[hot moss]

"In addition, Xenos can reset energy even though this is not mentioned in his skill descriptions" Nope. This is only visual and I don't even say bug. Simply a matter of combat animations kinda of 'reversing' time.

[bronze gust]

@river hound Where can you get this kind of information? I haven't read anything about it in the game yet. If that's true, it's still more than 3%.

[river hound]

I remember this from the guides back in season 1 og. That's how accuracy works, and the same goes for resistance.

[bronze gust]

@hot moss I have no idea what you're trying to tell me.
All I can say is that these resets happen from time to time, causing you to miss the set time. There is also no debuff that slows down the boss's loading time or that would cause you to be under such a debuff. Such small jerks can decide whether you can reset a boss 3 times in 18 seconds or land directly on the boss's skill mark and thus not reset anything at all.

[hot moss]

All I'm saying that what you see is the effect of playing boss skill animations. That does not affect your heroes ult in any way. Using Vinyara with timers is notoriously difficult because you have to count not only the effect of her ult steal but also the effect of Frozen debuff. And no matter how high acc is you can still fail sometimes which in her case means total desync 9 out of 10 times.

[bronze gust]

@hot moss Okay, if it has no effect on Vinyara and the boss is also slowed down by frost, then she would have to use her ultimate too early rather than too late. In such cases, she is too late and ends up not landing before the skill mark, but directly on it or just behind it.