Hope this works how I want it.
1) You sacrifice this as a cost for some effect
2) Once this becomes sacrificed, it's ability triggers and sends it yo your hand rather than your graveyard.

Looks about right; I think if an opponent controls it, then sacrifices it, it gets confused for a moment and then ends up in your graveyard where it belongs. Maybe "its owner's hand"?

made the change, thanks

This is templated making the same mistake that many cards do, of coming down somewhere in between a replacement ability ("instead") and a triggered ability ("whenever").

I assume this is meant to replace the go-to-graveyard part of being sacrificed, so that it never hits the graveyard in the first place? In which case you want:

> If ~ would be put into a graveyard by being sacrificed, return it to its owner's hand instead.

Alternatively, if you want it to hit the graveyard and have an ability trigger and go on the stack that will bring it back when it eventually resolves:

> When ~ is sacrificed [or probably When you sacrifice ~], return it from its owner's graveyard to its owner's hand.

The first option applies before and during the sacrifice action and modifies what Ashnod's Altar does as you're paying the sacrifice cost. The second option lets the sac happen in the normal way but triggers afterwards and brings it back afterwards.

The card itself is nicely balanced. It looks like a heck of an engine, but "Sacrifice a creature" costs already assume creatures are fairly disposable, so I can't see very much that's broken with it. The key is that going back to hand is a sensible limit on the resources; if it went straight back to the battlefield that would be absurdly broken.

Well, if you want to recurse it, you need to come up with and probably an orrery as well.

And evil templating. "If" instead of "When" just reads wrong on a repeatable action.

I went with the first version as I wanted it to avoid the graveyard altogether.