#izzet-chaosmage

[magicjudge]

At what point do you pay costs for activated abilities? And could you activate Steel Hellkite's second ability, then pay for the cost by sacrificing it to Ashnod's Altar? Thanks for your great work!

When you activate an ability, you pay costs for it at the very end, after it has been put on the stack and had targets (if any) chosen for it, etc. Generating mana and paying costs are the last two steps, so you’ll be able to sacrifice Steel Hellkite to Ashnod’s Altar to pay for its own activated ability.

[magicjudge]

If I control both Patron of the Vein and Kalitas, Traitorof Ghet & a creature an opponent controls dies, are there rules for determining which effect happens, or can I choose?

Kalitas wins here. His ability is a replacement effect whereas Patron of the Vein's third ability is a triggered ability. 

When a creature an opponent controls would die, Kalitas's ability replaces that creature dying with it being exiled and creating a zombie token instead. The creature doesn't actually die, so Patron of the Vein doesn't trigger here.

Shame on you, Kalitas. Hoarding all that blood for yourself while all the other vampires go hungry? Rude.

Also, note that Kalitas’s replacement effect only applies to nontoken creatures, so when an opponent’s token dies, Patron of the Vein will be able to exile it since Kalitas doesn’t care about it.