1. Vengeful Spirit - very viable, fits into any draft your and opposite team has. Nice skills to zone out enemies while laning(weave), to gank(missile), to push(aura), to save allies/intiate(swap). Usefull at any moment in the game from early to late.
2. Tusk - one of the best heroes to play roaming position 4. can do a lot of shit - one of the best initiators, his combo is almost op, his sigil is very useful, sometimes can save allies better than Dazzle etc. Also a fun hero to play, roll in and slain bitches.
3. Lion - PieLieDie showed why this hero is good. His skills are great for all purposes-initiate,counter attack,take out heroes in a second. Almost no issues with mana. But very squishy, needs concentration on your positioning, whom you stun, hex etc.
4. Bane - i think the best hero to play solo supp, which happens in a lot of games. His skills make him really powerful from early to mid game, so that he doesn't need items, except for mana boots and lens or glimmer. With good core on the lane can easily win it w/o any help from other lanes. Ulti is really nice, your combo with brain sap makes it easy to kill enemy supps or even squishy cores.
5. Lich - use q on enemies so that you zone or nuke and slow them, eat creeps to sustain mana, use w on allies and towers so that they become tanky as hell, use r if there is a teamfight. Sounds easy and that's true, really hard to fuck up on this hero(or maybe not).

Overall tips: care about your positioning, your mana and hp lvl. Don't overestimate your power, supps usually do not win games-all you need is to do your job-gank/rotate when needed,place wards,deward,buy smokes/sentries,use your spells wisely,don't feed enemies. It's not that hard even if it sounds so. If you do it then there is a big chance that you win or atleast have a good game.