Uh gonna cut to the point here, sustain is crap, it needs a boost, its really bad on ifrit-egi, since he likes every aoe and likes to be poisoned alot in melee range.
And before anyone says, no many don't want to use garuda, i prefer ifrits shield/stun.
Currently, the sustain gives us 3 ticks sometimes 4, clearly not enough to keep ifrit/titan up.
So yeah, needs a buff, id say 10% of summon's HP for 20 seconds.