Idea: Use Zenurik passive (60% heavy attack efficiency) + [Focus Energy] (40%) OR riven with at least 30% to get 90% efficiency (thats the cap)
This will allow you to use heavy attacks that only consume 10% of combo counter ( equals 20 combo points )
Throw to get 20 combo counter, heavy to spend 20, repeat ... balancing betwen 200 and 220 combo for max multi
[Xoris] has infinite combo duration => at max combo you get Heavy Attack Multiplier 12.0x,

Toxin + Eletric from Residual arcane => corosive => more statuses xD
i know that CO dosnt apply to the explosion, but still, i have to throw that thing and punch thru before explosion