You can select "Metal Reflect Slime" with "Last Turn" and it will not be sent to the GY.
A "Metal Reflect Slime" equipped with "Heart of Clear Water" will be destroyed by "Mystical Space Typhoon".
You cannot activate "A Deal with Dark Ruler" when "Metal Reflect Slime" is destroyed and sent to the GY because it is a Trap Card in the GY.
While "Metal Reflect Slime" is treated as an Effect Monster Card, it will count as 1 card for "Spatial Collapse".
When "Inferno" destroys "Metal Reflect Slime" in battle, its effect does not activate.
You can activate "Chain Disappearance" when "Metal Reflect Slime" is Special Summoned. The Special Summoned "Metal Reflect Slime" and all copies of "Metal Reflect Slime" in the Deck will be removed from play.
When "Absorbing Kid from the Sky" destroys "Metal Reflect Slime" in battle, its effect does not activate because "Metal Reflect Slime" is a Trap Card in the GY.
When you activate "Call of the Earthbound" and chain "Metal Reflect Slime", a replay will occur when "Metal Reflect Slime" is Special Summoned. If the opponent decides to attack with the same monster, you will select its attack target.
If "Metal Reflect Slime" becomes a Machine-Type Monster with "DNA Surgery", you can select it with "Machine Duplication" but you will not be able to Special Summon any cards because "Metal Reflect Slime" is a Trap Card while in your Deck.