Animation-delay not working properly on iOS, why?

Question

I have following code in the snippet. It works fine everywhere except iOS - I suppose the problem is in animation delay as some of animatad paragraphs are animated in the same time. You can see the demonstration http://stassabiomassa.com/ (the words coming out of left dragons' head).

Does anybody know the issue? Please help. Thanks!

.dragon-speech:nth-of-type(1){
    -webkit-animation-name: dragon-speech_animation;
    -moz-animation-name: dragon-speech_animation;
    -ms-animation-name: dragon-speech_animation;
    -o-animation-name: dragon-speech_animation;
    animation-name: dragon-speech_animation;
    -webkit-animation-duration: 10s;
    -moz-animation-duration: 10s;
    -ms-animation-duration: 10s;
    -o-animation-duration: 10s;
    animation-duration: 10s;
    -webkit-animation-timing-function: linear;
    -moz-animation-timing-function: linear;
    -ms-animation-timing-function: linear;
    -o-animation-timing-function: linear;
    animation-timing-function: linear;
    -webkit-animation-delay: 0.2s;
    -moz-animation-delay: 0.2s;
    -ms-animation-delay: 0.2s;
    -o-animation-delay: 0.2s;
    animation-delay: 0.2s;
    -webkit-animation-iteration-count: infinite;
    -moz-animation-iteration-count: infinite;
    -ms-animation-iteration-count: infinite;
    -o-animation-iteration-count: infinite;
    animation-iteration-count: infinite;
    -webkit-animation-fill-mode: forwards;
    -moz-animation-fill-mode: forwards;
    -ms-animation-fill-mode: forwards;
    -o-animation-fill-mode: forwards;
    animation-fill-mode: forwards;
}

.dragon-speech:nth-of-type(2){
    -webkit-animation-name: dragon-speech_animation;
    -moz-animation-name: dragon-speech_animation;
    -ms-animation-name: dragon-speech_animation;
    -o-animation-name: dragon-speech_animation;
    animation-name: dragon-speech_animation;
    -webkit-animation-duration: 10s;
    -moz-animation-duration: 10s;
    -ms-animation-duration: 10s;
    -o-animation-duration: 10s;
    animation-duration: 10s;
    -webkit-animation-timing-function: linear;
    -moz-animation-timing-function: linear;
    -ms-animation-timing-function: linear;
    -o-animation-timing-function: linear;
    animation-timing-function: linear;
    -webkit-animation-delay: 2.2s;
    -moz-animation-delay: 2.2s;
    -ms-animation-delay: 2.2s;
    -o-animation-delay: 2.2s;
    animation-delay: 2.2s;
    -webkit-animation-iteration-count: infinite;
    -moz-animation-iteration-count: infinite;
    -ms-animation-iteration-count: infinite;
    -o-animation-iteration-count: infinite;
    animation-iteration-count: infinite;
    -webkit-animation-fill-mode: forwards;
    -moz-animation-fill-mode: forwards;
    -ms-animation-fill-mode: forwards;
    -o-animation-fill-mode: forwards;
    animation-fill-mode: forwards;
}

.dragon-speech:nth-of-type(3){
    -webkit-animation-name: dragon-speech_animation;
    -moz-animation-name: dragon-speech_animation;
    -ms-animation-name: dragon-speech_animation;
    -o-animation-name: dragon-speech_animation;
    animation-name: dragon-speech_animation;
    -webkit-animation-duration: 10s;
    -moz-animation-duration: 10s;
    -ms-animation-duration: 10s;
    -o-animation-duration: 10s;
    animation-duration: 10s;
    -webkit-animation-timing-function: linear;
    -moz-animation-timing-function: linear;
    -ms-animation-timing-function: linear;
    -o-animation-timing-function: linear;
    animation-timing-function: linear;
    -webkit-animation-delay: 4.2s;
    -moz-animation-delay: 4.2s;
    -ms-animation-delay: 4.2s;
    -o-animation-delay: 4.2s;
    animation-delay: 4.2s;
    -webkit-animation-iteration-count: infinite;
    -moz-animation-iteration-count: infinite;
    -ms-animation-iteration-count: infinite;
    -o-animation-iteration-count: infinite;
    animation-iteration-count: infinite;
    -webkit-animation-fill-mode: forwards;
    -moz-animation-fill-mode: forwards;
    -ms-animation-fill-mode: forwards;
    -o-animation-fill-mode: forwards;
    animation-fill-mode: forwards;
}

.dragon-speech:nth-of-type(4){
    -webkit-animation-name: dragon-speech_animation;
    -moz-animation-name: dragon-speech_animation;
    -ms-animation-name: dragon-speech_animation;
    -o-animation-name: dragon-speech_animation;
    animation-name: dragon-speech_animation;
    -webkit-animation-duration: 10s;
    -moz-animation-duration: 10s;
    -ms-animation-duration: 10s;
    -o-animation-duration: 10s;
    animation-duration: 10s;
    -webkit-animation-timing-function: linear;
    -moz-animation-timing-function: linear;
    -ms-animation-timing-function: linear;
    -o-animation-timing-function: linear;
    animation-timing-function: linear;
    -webkit-animation-delay: 6.2s;
    -moz-animation-delay: 6.2s;
    -ms-animation-delay: 6.2s;
    -o-animation-delay: 6.2s;
    animation-delay: 6.2s;
    -webkit-animation-iteration-count: infinite;
    -moz-animation-iteration-count: infinite;
    -ms-animation-iteration-count: infinite;
    -o-animation-iteration-count: infinite;
    animation-iteration-count: infinite;
    -webkit-animation-fill-mode: forwards;
    -moz-animation-fill-mode: forwards;
    -ms-animation-fill-mode: forwards;
    -o-animation-fill-mode: forwards;
    animation-fill-mode: forwards;
}

.dragon-speech:nth-of-type(5){
    -webkit-animation-name: dragon-speech_animation;
    -moz-animation-name: dragon-speech_animation;
    -ms-animation-name: dragon-speech_animation;
    -o-animation-name: dragon-speech_animation;
    animation-name: dragon-speech_animation;
    -webkit-animation-duration: 10s;
    -moz-animation-duration: 10s;
    -ms-animation-duration: 10s;
    -o-animation-duration: 10s;
    animation-duration: 10s;
    -webkit-animation-timing-function: linear;
    -moz-animation-timing-function: linear;
    -ms-animation-timing-function: linear;
    -o-animation-timing-function: linear;
    animation-timing-function: linear;
    -webkit-animation-delay: 8.2s;
    -moz-animation-delay: 8.2s;
    -ms-animation-delay: 8.2s;
    -o-animation-delay: 8.2s;
    animation-delay: 8.2s;
    -webkit-animation-iteration-count: infinite;
    -moz-animation-iteration-count: infinite;
    -ms-animation-iteration-count: infinite;
    -o-animation-iteration-count: infinite;
    animation-iteration-count: infinite;
    -webkit-animation-fill-mode: forwards;
    -moz-animation-fill-mode: forwards;
    -ms-animation-fill-mode: forwards;
    -o-animation-fill-mode: forwards;
    animation-fill-mode: forwards;

}

<p class="dragon-speech">Муха!</p>
<p class="dragon-speech">Муха бесит!</p>
<p class="dragon-speech">Пришлепни!</p>
<p class="dragon-speech">Придави ее!</p>
<p class="dragon-speech">Муха!!!</p>

Answer 1

Solved it. Works properly if set negative value to animation delay. For each ":nth-of-type(n)" as follows:

animation-delay: -9.8s;
animation-delay: -11.8s;
animation-delay: -13.8s;
animation-delay: -15.8s;
animation-delay: -17.8s;