I've used this card in my deck in several hundred games and I've managed to get it special summoned exactly once.
Let's answer some questions: Gravekeeper? Nope. Keith's dragons? Nope. 4 starred ladybug? Nope. Any spell/trap effect? Nope.
I can't remember exactly which card triggered the effect; I think it was an insect type, but I might be wrong. It wasn't anything used in any of the common pvp decks and it very specifically said on the card "target and destroy one enemy monster" as its effect (I think it was it's on death effect).
Dragonic Knights' effect says "when the effect of an opponents monster is activated that targets and destroys a card(s) you control", so it should therefore activate if one card or more cards are destroyed, whether it be monster or spell/trap.
Flip effect not able to activate summon condition because only flip may not destroy any of your card(s). You must have a card in the field and destroy by opponent's monster effect. I doubt how can it happen... I think the activate condition of this card is UR, although the card placed in R. :p
As for the flip effect it depends on whether or not it targets and destroys a card you control (this won't trigger the summoning condition at all if the flip effect is activated in the middle of the damage step)as for the rest of your statement please use proper English not engrish(broken English) or just post in your own native language.
As may of you i tried to special summon this card with many other cards, but it never happen...
The only two things that i can think about this are this: 1 there's a bug in the game 2 if you go and check on the page of this card on fandompedia you could see in the section of the ruling that this card can only special summoned when your opponent target and destroy your cards, not yourself
It did work for me, but I can't even remember what card my opponent used to trigger it. And I have never been in another situation where it's effect could have been triggered. So I ended up taking it out of my deck.
as a dragon lover, i actually find this card useless though :(
Ok, so most of the card effects that target and destroy a card won't trigger this card's effect... so, isn't it easier to build a list of cards that can actually trigger this card special summon effect? I've never been able to special summon this monster with his effect, so I can't even start the list, but if anyone here could start it, sure sooner or later we all will be able to use this card better.
Oh, and before someone get angry with me because of the "engrish", yeah, it's not my 1st language so I'm sorry if I offended someone. It's just that It's not easy to find answers in any brazilian blogs. Anyway, I hope everybody can understand me and focus in answering the all questions 4 new and old players alike. Thnx
Another situation where this card won't work is when flip side effects are activated thanks to an attack. Since flip effects activate in the middle of the damage step, you can't use the effect of Dragonic Knight to counter the activation of Man-Eater Bug or a similar monster or any of their like. It's a different story when the opponent flips the monster on his own.