if u are in a mini sins arent as much of a problem if u manage to lure them in a corner, as long as u kept mark on everyone your heals should be decent. first step is to dot and wait for overload to activate, if u lucky u have managed to find the space to snare him before u throw instas and mark to activate overload. when u crit, u gain instant ice strike while he gains immunity, IF u hold him off he will be in a position where he will seek to activate dull pain(if he doesnt use instant ice strike) use freeze, he will cc break it so make sure u get some distance the second ur cc lands, make him chase u that way u can manipulate using fear. if he charges in while u are fearing: bingo u have time for some major deeps and self heals. if he kites, dont complete ur fear, hold him at bay and keep him doted and keep healing your self. make sure to never use ice strike while dull pain or overload is active and to keep him doted any chance u get(a bit like u wont see healers without their blue) its your kiting power forcing the enemy to rush in and attempt to precipitate their dps. personally id use purge on gc so that he cant land sds stun+bomb. most sins will try to land gc, and with that snare its easier to land sds. when u break the snare u can kite and ultimately cc easily(more often then not theyll sqeeze in bomb while u are ccing so, u know, life strike)
*edit* dont use ice strike unless its instant, use gangerous stench and ruin instead
1 last thing, u can use frost blast to precipitate the use of aod. ideally sin uses aod on frost blast so that u have longer cc power when he is snared