Omen Skin Pack Buy Options

Hello, i got a couple questions about these skin packs.

First in your announcement you said that the skins were going to be available for purchase using ONLY Royal Crystal UNTIL April, Does this mean the skins will become perma unavailable or we will be able to buy them using blue crystals after april, like any other skins?

Also why there isnt a blue crystal option for it? I replaced my Royal Crystals for blue crystals because of this same skinline for it to come exclusive for royal crystals…