You may use this card to return Fusion Monsters with no effects to the Extra Deck.

If you have 4 Effect Monsters and 1 Normal Monster with 1500 ATK in your Graveyard, you can activate this card and return the 1 Normal Monster to your hand.

If you have 5 Normal Monsters in your Graveyard, you can activate "Backup Soldier" and chain a second "Backup Soldier" before the first resolves, because the 5 monster requirement only needs to be fulfilled at activation. This would allow you to put all 5 monsters in your hand, 3 with the first "Backup Soldier" and 2 with the second.

If your opponent activates "Delinquent Duo" and you chain "Backup Soldier" with 2 pieces of Exodia and retrieve the other 3 from your Graveyard you win the Duel before you have to discard for "Delinquent Duo". This is because you check for victory conditions in between steps in a chain, (but not in between two separate effects of a single card like "Graceful Charity").

Deck Devastation Virus:" If you have the four limbs of Exodia in your hand when your opponent activates "Deck Devastation Virus" they will be destroyed. You can use two "Backup Soldier" to return them to your hand and they will not be destroyed (they were not drawn). If on your next turn you then draw "Exodia the Forbidden One" you will win the game before "Exodia the Forbidden One" is destroyed by the effect of "Deck Devastation Virus".

Disappear:" If you chain "Disappear" to your opponent's "Backup Soldier" you can remove one of the targeted monsters from play, but the remaining two (or less) go to the opponent's hand.

Necrovalley:" "Necrovalley" WILL negate the effect of"Backup Soldier"