I've been playing guin for awhile and here are my takeaways:

1. i always buy that physical armor that increases your move and phy+magic def as it helps me not get one shotted as a 3rd item.
2. most of the time i survive their burst so i either run away or if i have feather; i stay and basic attack all depending if i think i can win or not.
3. if there are more phy attackers; i buy another phy armor; or if there are more magic attackers i buy athenas shield. yes; my burst will be much less but at least i have a chance with DPS when i miss by s2 or my burst isn't enough.
4. any good player with a hero can kill or avoid me; i just learn from my mistakes and target other less experienced players in their team.
5. i use execute as a battlespell all the time instead of purify so i can afford to get an armor and still be able to burst enough to kill the enemy.
6. with one phy armor i feel confident in going 1on1 with most phy assasins and fighters even zilong. I would only fight zilong if i'm able to land my s2 on him first; else i run away.
7. i hate wanwan as she has a free purify and usually has shield battlespell. i don't guin if the enemy picks her. I also hate HC because i cannot quickly cast ult after i successfully land my jump due to his silence.
8. ML is not a 1v1 game... get a friend to help you.
9. unless you against a pro zilong; he wouldn't have his flip skill ready all the time; so you have to hide and gank him when you think he is distracted. You of course need to not show yourself to him until then.