probably mentioned already, but wanted to say its pretty easy to deal with the invincible/perfect dodge if all mobs are slept.
Pull away Aegis and start damage. When he pops Invincible, pull the Mandau and start working on him. It's a cakewalk even on VD to hold 2 mobs. Once the Mandau pops Perfect Dodge, Invincible should have worn and you can go back to working on him. Once Aegis dead, finish off Mandau. Basically a simple way to deal continuous DPS rather than losing time.
Excalibur doesn't haven't to be an immediate loss. My RUN is geared "ok", but played worse hehe. Was tanking VD last night and with good DDs Battuta will last the duration of time it takes to put down Excalibur. Yes, its not 100% like shadows but only died 1 out of 4 times we saw it once using Battuta to deal with the Added effect of 14k+ per hit.
If you're capable of stunning those moves, certainly it will be faster. Just giving options.