Penetration and cast level. Also, blood vengeance.

[PvK]

I don't know for sure, but my assumptions until told otherwise are that your three examples are all equally hard to resist, and that Blood Vengeance is just a state that doesn't remember what power level of magic caused it. But I have no special knowledge.

[Wish]

i would also believe that all three examples have the same penetration.

blood vengance has a rating (like awe and fear) which shows how difficult it is to overcome for the attacker. someone casting the spell gets blood vengeance 0, angel of fury has blood vengeance +2. this rating does not go up when cast by a powerful blood mage, so i am guessing the answer is no.

[llamabeast]

No, they won't all have the same penetration I think, because the bonus from extra magic levels is (number of extra levels / 2).

So: B4 mage casts hellbind heart - MR roll against penetration 11 (the default 10 + 1 for two extra levels)
B3 mage with spell focus: penetration 11 again (10 + 1 for spell focus, +0 for extra magic levels, since they're rounded down)
B2 mage with eye of the void: penetration 12 (10 + 2 for eye of the void)