How many creatures can Summon Warlock Ally summon?

Question

The spell Summon Warlock's Ally allows you to summon a creature associated with your pact; however, from what I can tell there is more than one option for that. In the above link, you'll find the Shadow Lurk which seems to be open to all Warlock's regardless of pact, the Wood Woad Guardian which is open to Fey pact and I've also found Satyr of the Night which seems to be available to Fey pact as well.

Can a warlock summon any of these creatures it wants? Do you choose at the time of summoning? Else, do you choose beforehand and become stuck with that creature permanently after the fact? Are there other options available that I haven't found yet?

Answer 1

I don't have a DDI account and can't find Satyr of the Night in a book but Shadow Lurk is only available to a Gloom Pact warlock.

In any case, I do have the book that contains the Summon Warlock's Ally power and it says;

Effect: you summon a creature associated with your pact.

If there is more than creature available for your pact, you choose whichever one you want each time you use the power, so you aren't stuck with just one permanently.

For instance at level 25 a Fey Pact Warlock gains the ability to summon a Frostblight Treant Protector using Summon Warlock's Ally, so you can choose whether you want to summon that or your Wood Woad Guardian at the time of the summoning.