Goblin Welder + Arcbound Overseer + Triskelion

[m03]

Pretty simple question:

Goblin Welder + Arcbound Overseer in play, and a Triskelion in the graveyard. I tap Welder, sacrificing Overseer and putting the Triskelion into play.

Am I able to target the Triskelion with the goes-to-graveyard ability of the Overseer (putting the +1/+1 counters on the fresh Triskelion)?

[Van Phanel]

Actually: Yes

Modular will wait to be put on the stack until after Goblin Welder's ability is fully resolved. Only at that time you have to choose a target and Triskelion is in play.

[Illissius]

This is because the exchange happens simultaneously: the sacrifice of one artifact and bringing back the other both happen as part of the resolution of the same ability, and triggers only go on the stack after the ability has resolved. If Goblin Welder's ability read instead as something like: "T, sacrifice an artifact: Return target artifact from your graveyard to play.", this wouldn't work.

And yeah, Welding an Overseer into a Triskelion with Anger in your graveyard is fucking awesome.