I love first strike. It sucks that I need to overcost this so much.

Three power of first strike, any time you have 4 mana available, isn't overcost, it feels like a fantastic bargain. White does get the cheapest mid-size first strikers though, so maybe.

But a 3/3 First Striker for 5 mana? The 4 mana discount requires another Ancestry attacker.

Oh sure, you have to be playing the mechanic to play the machanic. It's parasitic. But it turns on with only a snigle one, so it's not like you need to absolutely stuff your deck with them.

I agree you do need the high initial cost to make up for the "And then I bring it back, forever" portion. It just encourages people to find other ways of getting it into your graveyard.

It turns on with 2 though, you need an attacking Ancestry creature and one in the yard. If the opponent doesn't want you rezzing each turn they just need to kill the non-remnant one and the others will be sacrificed.

Yeahl but it turns back on again as soon as you get another one. Not saying you don't need some - just that you don't need every single creaure to be ancestral. Which is less parasitic than the mechanic might otherwise be.

Are you saying Ancestry ought to trigger with every attacking creature?

No; I'm saying this is fine as it is. One single live attacking ancestral creature is needed, and the whole mechanic turns on.

So 5 or 6 in a deck (or 3-4 in a 45 card draft deck) is enough for it to be quite likely to be available to you. The more you add, the more dead creatures you'll have to choose from, and the more resilient you are against someone deliberately trying to turn it off. But it's risky to try to turn off; since the thing you kill is then available to come back itself. So maybe you're better off trying to kill things that stay dead.