From the official Japanese Twitter account.

Seraphimon

Card NumberBT1-063Level6
Card TypeDigimonPlay Cost12
ColorYellowEvolution Cost3
Digimon TypeSeraphDP10000
AttributeVaccineRaritySuper Rare
StageUltimateArtist As’Maria
Main Effect[On-evolution] <<Recovery +1 (Deck)>> (Place the top card of your deck into the top of your Security.)
[During your turn] While your Security is 3 or more, this Digimon gets <<Security Attack +1>>. (Increase the number of Security this Digimon checks by +1.)
Source Effect

Slash Angemon

Card NumberBT1-062Level6
Card TypeDigimonPlay Cost11
ColorYellowEvolution Cost3
Digimon TypePowerDP8000
AttributeVaccineRarityUncommon
StageUltimateArtistTakumi Kousaka
Main Effect[On-evolution] During this turn, 1 of your opponent’s Digimon gets -8000 DP.
Source Effect

Booster 1 launches in Japan on May 15th, 2020.