After 1 Counter Trap Card you control has been activated and has resolved, you can Tribute 1 DARK monster to Special Summon this card from your hand. If this card is Special Summoned in this way, destroy 1 card on the field.
Special summoning this card is relatively easy since you just need to "activate" a counter trap card. You do not have to negate/destroy a card your opponent uses by the counter trap card. Also there are useful low level DARK monsters.
Is this card bugged? I was dueling against a friend and activated trap jammer during the battlephase when he activated a trap. After the trap resolved it didn't let me summon Dark voltanis, I had 2 monsters on board. One was a 4 star ladybug, the other was Man eating Treasure chest.
Treasure chest should have been a valid target to tribute. Was it because I was in the battlephase?
It doesn't have to say that; it's a matter of rulings. Since it doesn't directly alter ATK/DEF or counter a card, it can't be activated during the damage step in which for example a Trap Jammer counters a Mirror Wall.
Running this guy with counter traps makes you actually look forward to the opponent's backrow. You don't even care if you lose the duel, you already feel like you win when you negate the opponent's card and get this guy out.