dabbling in a thrall of Juiblex.. again

[Tenebrous Apostle]

I've been perplexed by this for quite a while. The thrall has a polymorph self ability at 8th lvl. It effectivly gives the character the ability to cast polymorph on hhmself as an 8th lvl caster at will. the only problem is it's a (Su) ability. Any ideas how to give it a little boost? preferably by hightening its caster level (If such a thing is possible). Thanks in advance ppl.

[awaken_D_M_golem]

(su) is rather good compared to (sp) or the actual spell.

Assume Supernatural Ability feat or
build in Metamorphic Transfer feat, are standards.

I forget off hand what early qualifying Thrall Of Juiblex has,
But it's something like kill your grade school playmate.

[Tenebrous Apostle]

+6 Fort, 4 ranks in escape artist, thrall to demon, willing deformity. U can enter at your 4th lvl. I'm trying to raise it's caster lvl so I can transform into bigger critters. That's my primary concern. Where is metamporphic transfer?

[Noliar]

Summon ooze and summon pudding (mmmn pudding) have no usage limit. Binder has a good fort save. Dahlver-nar is reachable with one level and a feat and lets you share damage with a nearby creature. Your own summons won't resist.

[zook1shoe]

Metamorphic Transfer (Expanded Psionics Handbook pg48)
Assume Supernatural Ability (Savage Species pg30)
Improved Assume Supernatural Ability (Savage Species pg35)

[Tenebrous Apostle]

The Metamorphic transfer feat is cool but it requires 5th manifester lvl.. My idea was Swashbuckler1/barbarian1/warblade1 so as to reach +6 base Fort. Which one should I substitute and with what? Avoid the swashbuckler since the lvl is needed for the class skill of escape artist, of which I'm required to have 6 ranks.