Don't believe what wikia says about darksoul this is how he works.
Before you read this, note that there is a large FALSE in front of the FALSE statement. That means the FALSE statement is FALSE.
There is a large TRUE in front of the TRUE statement. That means the TRUE statement is TRUE. TRUE means it is the ruling you should use.
FALSE: The effect of "XX-Saber Darksoul" can only activate the effect of "adding 1 "X-Saber" monster from your Deck to your hand" once, no matter how many
times it is sent from the field to the Graveyard. (This is not how the card works. You should not do this).
TRUE: The effect of "XX-Saber Darksoul" activates when it is sent to the Graveyard, although the effect is not applied until the End Phase. If it was sent multiple times during the turn, these effects can "stack up" and you can add 1 X-Saber monster to your hand for each time the effect activated. (This is how the card works! This is the ruling you should use!)
FALSE: The effect of "XX-Saber Darksoul" will not activate if "XX-Saber Darksoul" is not in the Graveyard during the End Phase which it was or would have
been sent to the Graveyard. (This is not how the card works. You should not do this).
TRUE: The effect of "XX-Saber Darksoul" activates when it is sent to the Graveyard. Assuming it actually made it to the Graveyard, it doesn't matter where Darksoul is during the End Phase. (This is how the card works! This is the ruling you should use!)
Source pojo
Before you read this, note that there is a large FALSE in front of the FALSE statement. That means the FALSE statement is FALSE.
There is a large TRUE in front of the TRUE statement. That means the TRUE statement is TRUE. TRUE means it is the ruling you should use.
FALSE: The effect of "XX-Saber Darksoul" can only activate the effect of "adding 1 "X-Saber" monster from your Deck to your hand" once, no matter how many
times it is sent from the field to the Graveyard. (This is not how the card works. You should not do this).
TRUE: The effect of "XX-Saber Darksoul" activates when it is sent to the Graveyard, although the effect is not applied until the End Phase. If it was sent multiple times during the turn, these effects can "stack up" and you can add 1 X-Saber monster to your hand for each time the effect activated. (This is how the card works! This is the ruling you should use!)
FALSE: The effect of "XX-Saber Darksoul" will not activate if "XX-Saber Darksoul" is not in the Graveyard during the End Phase which it was or would have
been sent to the Graveyard. (This is not how the card works. You should not do this).
TRUE: The effect of "XX-Saber Darksoul" activates when it is sent to the Graveyard. Assuming it actually made it to the Graveyard, it doesn't matter where Darksoul is during the End Phase. (This is how the card works! This is the ruling you should use!)
Source pojo