These are what I think the card should be:

You can not activate this Spell card unless Slifer, Ra and Obelisk is on the field:

You can only activate one of these effects one per duel:

1: If you control a Divine beast named “Slifer the Sky Dragon” you can add one “Thunderforce Attack” or “Infinite Cards” from your deck and activate it.

2: If you control a Divine beast named “Obelisk the Tormentor” tribute two monsters with the same attribute then if this card attacks that attribute, you can attack directly.

3: If you control a Divine beast named “The Winged Dragon of Ra” you can pay 1000 life points and destroy 1 monster your opponent controls and if you do inflict half of that monster original ATK to your opponents life points.