Which Vanguard Ike should I level up?

I would level up the +speed -resistance vanguard Ike because those are some good IVs. I have seen some builds that try to make vanguard Ike have high resistance but I don't think they work too well. I built my Vanguard ike with warding breath and quick riposte 3 and it works very well. So I would level the +speed one and use the neutral one for fodder.

Honestly, the +spd one, res isn't a big factor on V!Ike I feel. The +spd boon should help in general

Ye the + spd one. i have +spd -hp. So basically same magical bulk and he doesnt really miss the res since if he gets doubled he drops like a fly anyways
try to keep the neutral one as long as you can if u ever want to resort to a ftp walkthrough guide, if not then dont worry about it.