This is an incredibly strong combination when used with Aquamarine. With 2900 ATK and 4100 DEF, in addition to being a strong beatstick, it will form an incredibly strong wall afterwards to defend you until you're ready to attack again.
Summoning this card with "Particle Fusion" can make it stronger. When combined with the above strategy, it can be stronger still.
You can use this card with "Shield and Sword"/"Super Crashbug" to turn it into a 2600 ATK Monster without leaving it vulnerable on your opponents turn.
You can permanently switch the original ATK and DEF with "Inverse Universe" and activate "D2 Shield" after it switches battle position leaving it with 2600ATK/2800 DEF.
Alternatively, you can use "D2 Shield" first then "Inverse Universe" for a 5200ATK/1400DEF. If you're concerned about its DEF, then equip it with "Fusion Weapon" for a higher boost, giving you an almost-unstoppable monster with 6700ATK/2900DEF.
Tribute this card for the effect of "Gem-Knight Ruby", and return one of your opponent's monsters to lessen their defense.
Use Aquamarine as a fusion material monster using "Gem-Knight Fusion", then when it's send to the grave, use it's effect of return one card to the hand, use the effect of Gem-Knight Fusion to banish aquamarine an then bring it back with D.D.R. - Different Dimension Reincarnation to use it again as a fusion material monster and return another card to the hand.