https://pathofexile.gamepedia.com/Spell_Cascade_SupportSupported Skills have (25-16)% less Area of Effect
less is good
low is better
like cwdt-heartbound,
this build also: keep them gems low, for more disco and more damage and better more trolling at great effectivnissrates
Icestorm(or firestorm, depending on staff)-spell Cascade(low=better/less=good)-Intensify support(low=better/less=good)-concentrated effect-Unleash(for the waveclear)
-life leech-spell echo (5link or 7link, 4link can do aswell, skip conc effect if use 4link for lvling)
Posible a lvl1 spell cascade+lvl1 Intensify already allow to hit small boss without conc effect
allow phantams on kill support gem, for heartbound
you not realy need to keep the 2 support gems at lvl1, its about single target with 4 stacks of Intensify support, to get about -70%less AoE combined multiplied
on the first cast, you not need the less AoE, to keep your clearspeed up, leveling the gems helps.
-------------
Why not occultist, a bit of es-recharge
allow to just have 13%es-leech-rate-cap, witch requirer lower amounth of es-leech
keep the life-leech-rate at 20%
Corrupted energy jewel: 50%physical damage taken byepass es
selfdamage on ignite amu to start zoo, combined with heartbound loop cwdt-disco
Incoming damage, from physical or chaos: Mom, to support 20%leech rate life and %regen life+life on hit = 13%es-leech rate+es recharge(+es on hit)