As many of you would know, in a tempo deck kron gives you such a boon.
Free bodies, regardless of circumstance. It just makes overwhelming them and board pressure so much more easy.
However in a deck I built that swarms midrange powerhouses (tempo based) I found that kron just did not kick hard enough, the problem being was it died so often it was better at pulling answers and slowing your opponent down by a turn then actually pressuring some kind of threat.
For example, makantor + general = oh shit
Another aspect is the rng, yes frostiva has it’s own rng but at least you dont have to cross your fingers that you dont get another 2/2 frenzy in range of their iron dervish. I am not underplaying the power of kron, it demands an answer and throws 14 raw stats on the board the turn you play it. But it normally is a distraction.
In vanar, you are playing a card to tax their resources. This equates to winning the game via grinding them down rather then bursting them down from a superior position. This avenue of play lines in more with control rather then tempo (think silithar elder). I would not recomend this in a tempo deck that needs things to stay put.
Frostiva is a breath of fresh air, the stats it outputs are split rather evenly yet not to the point that the original body is useless, so when you want a target for wailing overdrive or razorback or aspect of the mountain ect you are more likely to find a 3/3 sticking then a 2/2. Yes it could be answered before you get anything at all from it and that is a risk you take, however in tempo you should have been at such a stage they would have answered your 4 drops and been suppressed by your removal… it enables tempo to a wincondition and the forcefield trait is essential as it allows you to plow through units until they can kill it in a two step process, this means you are gaining value consistently.
I believe the biggest boon is it is immune to damage based removal, it is very hard to pop and forget. The most readily available answers to it are range restricted and to kill it with their board is to multiply your board with stats, say 3 units trade into it you now have 3 3/3’s (vespyrs too if you run that kind of deck). Imagine it as the sojourner of tempo.
Kron is hands down the better card, when looking at it on a sheet of paper. But frostiva is in many ways the better pick for vanar (unless you want to play a kara grind deck that wins with tiger, but then again you could run anything in that).
It is in the end up to your judgement, but frostiva does not distract it destroys
Edit: it seems people didn’t see the parts when I assessed kron as the overall better card, if you skipped most of the post and are going off the title. I understand kron has provoke and gives immediate value, this post more covers the way frostiva handles it and how that works better for vanar in many cases