Personal Review
I've been playing Panth for a long time. I started with the common full damage spec(400+AD) we all know, which was Ok, however the lack of a high amount of HP made me very vulnerable. After many matches testing a wide range of combinations I have come out with a build which in my opinion makes Pantheon the perfect hybrid killer.
Summoner Spells
Flash is the greatest spell ever imo for any char. You can use it to get in and out of mass fights as well as surprising anyone who thought that was out of your "Aegis of Zeonia" hability (jump).
The other one; teleport, it works as a second ultimate if you manage to tp on hidden wards or teemos' mushrooms. With this spell and your ultimate you will be able to gank as much as you wish. It provides you total control of the map!
Tele Ganking mode on!
- When you come to play Panth in a 5man premade and the opposite team has a jungeler do as follows:
Start buy geting a ward or tell a mate to do so. This ward must get planted in the bushes near their red buff. When you see their jungler fighting against the red minion wait until his life drops to half. Then use teleport to rape it, and there we go, a nice early kill which will counter the enemies jungeler!
- As Panth's gameplay is very agressive at low lvl you should be able to get killing blows quite easily. I mean, imagine you've killed one or both heros in your lane, before lvl 6.
Teleport will give you the oportunity to, go back to base, restore yourself, buy the occult sowrd or speed boots and teleport to the other lane which is having some problems. (If u wanna defend teleport to the tower, but if u wanna gank teleport to a vision ward hidden in the bushes!) I usualy play 5on5 premades so I can manage to do all this teleporting stuff to wards and its great fun! This is a way to stack up occult marks easily.
- Onces u've reached lvl 6 and u've got your utlimate:
What happens, and what can you do with booth habilities availabe:
The order in which you use them depends on the situation, however imagine you wanna gank or help someone far away from you. You may use your ultimate, and once u've raped them,
(ohh **** a pair of smart guys are attacking my tower) you just teleport on a ward if you have one there and rape them too! Or if you havent got a ward, just teleport on your tower and they will ran away in cower bcouse you've got already 5-10 KB!
Best partner to go with and gameplay
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I've combined Panth with many different chars, however the most brutal combo i've ever playd with was Jana.
Jana must have exhaust (to stop enemies from escaping) and clarity (to provide panth a continuos pressure on enemies)
We must be very agressive right from the beginning. SPAM spear shot with Jana's shield on the weakest hero. At lvl 2, combining the jump with a white hit + spear shot wearing Jana's shield you ensure a kill blow. You may use exhaust on that target if you wish but it must be dead by now. Save it for the othe one. If they escape with flash don't worry you can still pwn them under tower with our block and instantly flashing back out of tower's range.
By lvl 3 is a total and unstopable ownage with HS + Jana's shield. ^^
I will provide further information =)
Hope you enjoy it !

Changelog
11/03/11
I've changed evasion seals for HP per lvl seals. They are, from my point of view, much more useful than evasion ones. In early game, when laning, you realy appreciate that extra HP per lvl with Panth. Furthermore, in late, game you end up with over 4k HP with life elixir and these HP seals which are great in order to have more AD when completed the build with Atmas impaler.
(over 350 AD)
06/06/11
Since last nerf, Panth has become extremely weak in early, yeah even more than before. This build continues to work however Panth's early gameplay must change.
Before the nerf, laning bott lane with an apropiate partner was the best option, however, now Panth must seek to go mid lane if possible. Get some kills in 1on1 ( as Panth is a great 1on1 char) and look for some ganking in top or bott lanes using your ultimate/teleport ;)