My pal is using a gilt-leaf archdruid and an aluren enchantment to get to the 7 druids he needs to trigger gilt leaf archdruid ability to take my lands. I wait till the 6th druid hits the board and cast a titan's presence on his gilt leaf archdruid to stall his combo and exile the creature. Now things get messy...how does this resolve legally...i dont want to play magic unfairly...we see that he doesnt have the 7th druid to respond by tapping 7 druids and taking my lands then letting the titans presence resolve...he then argued he had the aluren in play and should have been able to cast his 7th druid to complete his combo before responding to the titans presence ... please help!!
Based on how you describe the situation, he gets to flash in his last druid and steal your lands. You say you wait until the 6th druid hits the board, which means he can respond to your instant with the 7th druid and has 7 druids while your spell is still on the stack. Then he responds with his activated ability, it resolves, and then your spell resolves.
If you wait until he casts the 7th druid, you can respond with the removal, but if he has an 8th druid that fits Aluren's criteria, he can flash it in in response and still get the lands.
While you can cast Titan's Presence as you suggest, your opponent can simply respond by casting more Druid creature spells (with converted mana cost 3 or less) while Titan's Presence is on the stack, letting them resolve, and finally, if the opponent now has seven untapped Druids on the battlefield, tapping them using Gilt-Leaf Archdruid before Titan's Presence can even resolve.
But even if the opponent already has seven untapped Druids on the battlefield, you will hardly be able to stop the combo in this situation. If the opponent activates Gilt-Leaf Archdruid's ability, Titan's Presence won't keep it from resolving, since removing an ability's source from the battlefield doesn't counter the ability (C.R. 112.7a).
You can't exile creature spells with Titan's Presence, since you can't target them, but only creatures on the battlefield (C.R. 109.2). And while Gilt-Leaf Archdruid is "being cast", it's still a creature spell.
If you wait until he casts the 7th druid, you can respond with the removal, but if he has an 8th druid that fits Aluren's criteria, he can flash it in in response and still get the lands.
But even if the opponent already has seven untapped Druids on the battlefield, you will hardly be able to stop the combo in this situation. If the opponent activates Gilt-Leaf Archdruid's ability, Titan's Presence won't keep it from resolving, since removing an ability's source from the battlefield doesn't counter the ability (C.R. 112.7a).
http://media.wizards.com/2016/docs/MagicCompRules_04082016.pdf
For this particular situation, you will want to focus on 116. Timing and Priority and 405. Stack.
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