The Ragnarok team has given additional information to supplement the missing parts in our text.

About the required number of cards and use of default units:

You need to have one NFT for each piece in use, there will be no default characters.

A rental system will be in place to allow you to fill the gaps in your roster.

About pets summoning:

You can have a maximum of 9 pets simultaneously and can summon as many as your mana allows per turn.

About cards draw per turn:

The default amount of cards drawn after the first turn is one (1). There will be special abilities that can change this number.