This is a fantastic idea. This community has lost a lot of members to Covid and other things in the past year. A tribute hero to lost and beloved teammates is a really lovely idea.
Anubis, Egyptian god of lost souls would fit Sand.
Possible stats:
5* Holy, slow, Attack 500, Defense 850, Heath 1500
Special: Remembrance of those lost but not forgotten.
1st time, all Dead heroes would be revived at %75 attack, defense, health for 4 turns or until killed again.
2nd time all Dead heroes would be revived at %50 attack, defense, health for 3 turns or until killed again.
3rd, and all subsequent times, all Dead heroes would be revived at %25 attack, defense, health for 2 turns or until killed again.