it's for suporting Vengeful, you must play very agresive with you're strong carry. If you played vs durable hero you must play 3 vs 2 to kill them, remember Vendgeful is support and you must do everything for your carry, but don't foget take exp from free line and some money for items. Agressive, agressive and one more time agresssive.
Try to play party with your friend, if you play solo try to be communicative with your mates. GL HF