New fusion has the potential to fit your comp perfectly.

Shields + debuff protection. Try pulling Toragi the Frog as well for the ally protect + poisons to round up your comp. 

Congrats  on Martyr she is awesome

I use her  in my CB team and Spider team 20 

I rely on her mostly for counter and def down on enemy

Fusion is interesting but what worries me about it is that it doesn't really do much damage - it's mostly a support champ. Also, nobody else on my team does a shield, so the only part of my team that applies his passive would be himself.

Will depend a lot on what his skills' damage is based on. If they're DEF-based it could work maybe ...

With Rhazin and Toragi as your damage dealers you don't need more damage, you need to keep them alive for as long as possible. All the damage you need is gonna come from WM, GS and Toragi poisons extended by Vizier.

Brago

Nethril

Martyr

Rhazin

Vizier

If  you  desperatly  need  leech,  keep  Corpse  Collector  instead  of  Nethril.