The effects gradually increase over time peaking at a level similar to that of a Corsair rolling a lucky number without the job bonus for each type of buff, shown below. These effects stack with existing effects, including Phantom Rolls, Refresh, Regen, etc. The highest possible values will require a certain amount of summon skill, detailed below the chart.
Favor status granted
Maximum Increase (<317 Skill)
Maximum Increase (317+ Skill)
Maximum Increase (382+ Skill)
Maximum Increase (447+ Skill and Caller's Horn +2)
One example is for a level 75 Summoner there is a +1 Refresh potency with Diabolos's Favor when surpassing 317 Summoning Magic Skill.
Summoning magic skill used to break tiers of Favor must be constantly worn. With the above example, if you obtain a +4 MP refresh with Diabolos, and then switch into 316 summoning skill, it will reduce the potency down to +3, until you replace your gear to have 317+ skill.
In general, achieving the higher tier appears to improve the maximum effects of favor abilities by 25% (12HP to 15, 3MP to 4, 12% DA may become 15% (unconfirmed), etc)
Switching the potency of the Favor will cause it to flicker on your screen, and reset the duration it has been active if using a mod to record times.
After the favor 'flickers' off for a few seconds it does not reset to base amount. It reset to half and then resumes climb again. This is why it appears to take less time to re-cap. Tested with Titan and Diabolos. Base Def of 269 constantly resumed at 300 after 'flicker'. Cap (>317 skill tier) was 326, roughly half.
No testing has shown additional potency increases beyond the maximum effect attained at 317 skill.
See Talk page for more information.
The 317-Skill tier is not the only tier, but is commonly the most studied due to the Diabolos's Favor ability.