You only need one.
You just stack your alarms effect on top, then the drakes. Bouncing the drake to your hand, and taking off with everything else... or do I have it wrong again? Lemme download my updated comp. rulings from crystalkeep first to make sure.
I seem to remember in the days of Invasion that Mr. Sparkcaster was able to do his damage, then bounce himself back to your hand just by manipulation of the coming abilities.
But then again, you get extra mana all the same, while pumping that # of spells played during your turn thing. Lemme check: drake, add to spells, untap, bounce, drake, add to spells, untap, bounce, drake, add to spells, untap, bounce, drake, add to spells, untap, bounce, drake, add to spells, untap, bounce, drake, add to spells, untap, bounce drake, add to spells, untap, bounce, drake, add to spells, untap, bounce drake, add to spells, untap, bounce, drake, add to spells, untap, bounce drake, add to spells, untap, bounce, drake, add to spells, untap, bounce drake, add to spells, untap, bounce, drake, add to spells, untap, bounce..........
Oh my..... Brainfreeze would surely hurt like a mo'fo... Tendrils of Agony
and Hunting Pack? 1 bazillion 4/4 tokens in play? or 2 bazillion life loss/gain?
"Hey kid, wanna see a neat trick?"
410.10a - Comes-into-play abilities trigger when a permanent enters the
in-play zone. These are written, "When [this card] comes into
play, ..." or "Whenever a [type] comes into play, ..." Each time an
event puts one or more permanents into play, all permanents in
play (including the newcomers) are checked for any comes-into-play
triggers that match the event. [CompRules 2003/07/01]
So, in other words its all stacked as one event? so:
Drake comes into play...
Checking....
Drake targets itself for bouncing, Intruder Alarm say's he's come into play, etc, etc...
Resolve...
Drake Bounces, Intruder Alarm untaps everything...
418.2 - Continuous effects that modify characteristics of permanents do so
simultaneously with the permanent coming into play. They don't wait until
the permanent is in play and then change it. Because such effects apply
as the permanent comes into play, apply them before determining whether
the permanent will cause an ability to trigger when it comes into play.
[CompRules 2003/07/01]
Wait, wait, wait, wait.... So I do need two because the coming into play ability of the drake would resolve before it even triggers the Intruder Alarm.
But then again, he already came into play, and triggered the alarm...
G3.18c - When a permanent comes into play, first apply any replacement
effects, then apply continuous effects, then check to determine if the
current form of the permanent generates any triggered abilities.
But again we see that the bounce effect would be placed on the stack beforehand, and then the triggered ability of the Intruder Alarm would go on too... So it would still resolve because the creature did in fact come into play, and the Alarm doesn't care if it left play right after it came into play.
Train, Sefro, where art thou when I need thy guidance?