outside the hourglass

izi wrote:

That would mean that A can also play more pre range cards in the prevent phase of pre range pseudo step. Correct?

Its not a phase. Whenever there is damage dealt, a window opens to play cards that prevent damage. But only damage prevention cards, and only when there is damage that isn't yet prevented. You can sort of "respond" with prevention cards when there is damage dealt.

For the topic question, superior horrid form prevents damage, therefore it is playable in the damage prevention window. Since this all happens during pre-range, it doesn't conflict with horrid forms restriction of being playable only during pre-range step.

As per ruling linked by Kevin it is also possible to play non prevent cards. The question is whether the vampire inflicting damage can play those as well.

izi wrote:

As per ruling linked by Kevin it is also possible to play non prevent cards. The question is whether the vampire inflicting damage can play those as well.

Yes. Every player can (at least in theory) play any relevant card or use any relevant effect in every phase, per the sequencing rules. Of course, in the vast majority of circumstances, that doesn't happen because no-one has anything they want to do that can be played right then.