For Ionar I just stand still (though spread) while he's dispersed and heal through it. Don't attack, don't move, just heal :-) Once he returns, resume DPS'ing. When done that way he's really really easy.

For Loken just bunch up and DPS. Be full health when he Nova's and chuck AE heals right after (if you have to, pre cast the AE so it hits right after Nova) while continuing to DPS.