core 21 booster box MTG: Set 2021 — Rules of Play art cards found only in Collector Boosters Core Set 2021 Bundle Unboxing

The answer is usually "Friendship"

In this case though, we are using her as a more traditional 2 color commander and focusing on her other bonuses

It can be built as a lifegain commander, a Voltron commander, or even an angel typal commander

Slifer's is all about having cards in hand to power it up and anyone trying to attack it will often find themselves 2000 ATK points weaker, Obelisk is about having monsters on the field to sacrifice to nuke the opponent's field and Ra can big itself up depending on the number of Life Points you have or you can sacrifice Life Points to destroy your opponent's monsters and if you summon it through the effects of The Winged Dragon of Ra Sphere Mode, you can get over Ra's weakness of its contradictory effects by having Ra at 4000 ATK points if summoned that way

Event Coverage - August 17, 1997 - Wayback Machine 1997 World Championships Sell Sheet