Use this card while you have an "Elemental HERO Neos" on the field to use Contact Fusion to get out the Fusion of "Neos" quickly. However, due to the beatdown effectiveness of the ATK boost you may want to save this card for Main Phase 2 if it would be smart.
The best "Neo-Spacian" to use this card's effect with is, by far, "Neo-Spacian Flare Scarab" since "Flare Scarab" can, by its own effect, become very powerful on its own and it will boost the other card's ATK by the same amount that its own is being boosted.
You can actually Special Summon the "Neo-Spacian" to your opponent's side of the field in order to deal enough battle damage (for monsters that either cannot attack directly, for those whose effects are triggered when monsters are destroyed in battle and/or battle damage is inflicted simultaneously.)
Summon a "Neo-Spacian Glow Moss" to the opponent's side of the field with this card and attack it to draw one or more extra cards.
Use this card to Special Summon "Neo-Spacian Grand Mole" to the field and then use its effect to return it to your hand and activate this card again, boosting your selected monster further.