Scarab Gods Ability does not function Correctly
Scarab God has an ability which says "When The Scarab God Dies, return it to its owners hand at the beginning of the next end step"
Bug Reproduction steps
Play a game of Historic Brawl in MTG Arena with The Scarab God as your commander
Destroy your own scarab god with a destroy spell during your turn with any destroy spell
Decline moving scarab god to your command zone and allow it to be destroyed and moved to the graveyard
Move to your end step
Observe that scarab gods ability does not proc which allows scarab god to be returned to its owners hand at the beginning of the next end step.
This is one of the positives of Scarab God as a commander. You can allow it to die and cast it again from your hand for its base mana cost.
I chose this option when a player took all abilities from scarab god, destroyed my own creature knowing the ability would proc, and then it didn't return to my hand. At then beginning of my end step my commander was not returned to my hand and remained in the graveyard.
I would understand if it was clear that the ability wouldn't proc in Brawl if The Scarab God was a commander. But there is nothing that makes this clear and I wouldn't have made that decision if I had known this ability wouldnt proc.
In my opinion, this ability should function as it is stated on the card if player allows their commander to be destroyed normally and not returned to the command zone. The ability to exile cards from graveyards is expensive and at the base of cost of the card at 5cmc would require having at least 9 (or a total of 9 from artifacts or other sources) to be available to play the card and cast its ability on the same turn.
I would hope this would be changed so that Scarab Gods ability to return it to its owner hand at the beginning of the next step functioned if the player chooses to allow scarab god to die. Or, make it clear in some way by greying out the ability or something that this ability does not activate if the card is chosen as a commander.