This card uses the current ATK or DEF of your monster. This is beneficial when you use abilities and cards to increase your monster's ATK/DEF. Due to this being a Quick-Play Spell Card, it can be activated from your hand at any time during your turn as well as set on the field and activated on your opponent's turn. This becomes increasingly beneficial when it can be activated in the middle of a chain and prevent the loss of your monster to a card like "Fissure" or "Raigeki Break".
Use "Limiter Removal" to double the ATK of one of your Machine-Type monsters. Activate this card before your monster goes to the Graveyard, as it would be destroyed anyway by "Limiter Removal's" effect. (This is especially useful if used on a monster summoned with "Power Bond".)
"Union Attack" increases a monster's attack by all the other monsters attacks that are face-up attack position on your side of the field while during the Battle Phase. Activate while leaving the Battle Phase to avoid missing the ability to attack. Use it with "The Winged Dragon of Ra" to gain back the life points used.
"Frog" or "Wetlands" based Decks can benefit with this card when you Special Summon "Junk Warrior" with "Junk Synchron". Just having "Wetlands" on the field will increase the ATK of "Junk Warrior" by 1200 for each affected monster on your field. With "Submarine Frog" in triplicate, that is an additional 7200 ATK in addition to the original 2300 of "Junk Warrior". It is thus a great monster to turn into Life Points if your opponent tries to destroy it.
"Wight"-based Decks can use this too. "King of the Skull Servants" can revive itself if it would be destroyed by battle. By effects, it has no DEF. Instead, use this card and gain 1000 Life Points per "Wight" card in the Graveyard. This can become as much as 11,000 and the Deck can already have many ways of reviving the "King".
Another card that helps is "Unity". This card can be activated during the Damage Step to increase your monster's DEF and then use this card during the End Phase to gain a load of Life Points equal to the entire amount of DEF all your monsters have.
If you have a monster that gains ATK based on the difference in player's Life Points, such as "Neo-Parshath, the Sky Paladin" or "Ancient Sacred Wyvern", you can use this card to gain Life Points equal to that monster's current ATK. Then revive it with "Call of the Haunted" or another card so that it will essentially have its ATK increased greatly. (This also has the added benefit of removing cards that are targeting that monster or lingering effects on that monster.)
This card works well with Ritual Monsters, as you can typically chain this to their destruction and gain 2500-3300 Life Points.
This card is a great way to counter "Lava Golem". Not only can you remove it from your field, thereby getting rid of the 1000 damage per turn, you also gain 3000 Life Points.
This card can be used in a "Hieratic" Deck. Not only you can protect your Dragons against cards like "Bottomless Trap Hole" or "Dimensional Prison", but you will also gain Life Points AND will activate the effect of the Tributed monster.
Use this card with "Grapha, Dragon Lord of Dark World" while you have another "Dark World" monster on the field. Tribute "Grapha", then return the other monster to your hand to Special Summon "Grapha" from the Graveyard, then Normal Summon the other monster from your hand.
Use this card with "Gandora the Dragon of Destruction" after you attack. You can deal a usually strong blow to your opponent while gaining the life since it will destroy itself anyway at the end of your turn.
This card helps you to (re)gain Life Points to pay LP costs i.e. in a "Toon" Deck or in combination with "Brain Control".