[Taqwus]

You can't actually combine Sun Slayer with a shield on anything except an Ettin (or Ettin Mandragora) or Nataraja chassis, as Sun Slayer is a two-hander. One might note that it also doesn't drain life, unless you forgo the attack and use it to cast drain life, and therefore does not reinvigorate or heal the user. It is a fun toy, however, combined with the aforementioned Bone Armor and some other source of decent prot like Amon Hotep or an Invulnerability spell.

One might note that high def is meaningless against spells (and there are unresistable high-damage spells like Magma Eruption (or whatever it's called) and Gifts from Heaven, as well as unresistable paralysis from Petrify... which also negates all defense while it's in effect, as would unconsciousness caused by Drain Life spamming), against missiles (although these usually won't be that damaging, except for the Black Bow which causes unresistable feeblemind), and the Harvest Blade (which automatically hits, and automatically cripples as well). High def is good, but not unbreakable.