League-of-legends – Whats with the spider helmet

Boots are a specific case. You can't have more than one movement buff from any kinds of boots at all.

As for other items with UNIQUE passives, as long as you don't have the exact same item, they all stack on top of each other.

Apparently, there are other exceptions as well. From the wiki:

Unique effects that do not cumulate among differents items include Movement Speed effects from boots (only the best effect applies), proc effect of Sheen, Lich Bane and Trinity Force, and the mana gained from Tear of the Goddess, Manamune and Archangel's Staff.

I dont know which article you are refering too, but M5 did this in pretty much every tournament they played in. M5 was the first team that got Oracles on their jungler in ~80% of their games, no matter if ahead or not. You can probably watch any M5 tournament game and see Diamond running around with an Oracles.

Even tho Udyr has a lot of diversity, he is played only in 2 ways, with one way beeing more of an soloq style(Tiger Udyr, only works against "bad" enemies on lower elos) and the only competetive way Udyr was ever played is Phoenixdyr.

For Masteries, you use 0/21/9, grabbing general tankyness in deffense (with MS!) and MS and increased Buff duration ins Utility. Udyrs role is to tank. You dont go for dmg, your base dmg will be enough for the first 30 min without any problem. For Runes, the best choice is MS quints, AS marks, Armor seals, MR/lvl glyphs. You can switch out the MS Runes, but I think pretty much everyone agrees that Udyrs biggest weakness is getting kited and thats nearly impossible with all the MS from Runes/Masteries. BTW: These are the Runes/Masteries Diamondprox used in the recent tournament as well.

You usually want to build Udyr as tanky as possible, since thats your main task in teamfights. You start with Boots 3 Pots, go for 2 fast gp10 Items (HoG and Philo) and then build situational items. If you are ahead you want to grab an oracles and a Aegis as soon as possible, Aegis can be grabbed if beh ind as well, but if your support planed on getting it, you can skip it (if behind) and get other items, like Randuins, Frozen Heart, GA against heavy AD teams; Wits End, Banshees, Force of Nature against heavy AP teams. If you feel your team needs dmg you can go for Trinity Force or Wits End, Frozen Mallet is a good Item Choice if the enemy is very mobile (eze, ahri, shyvana) and you need a way to stick to them. You can also upgrade your Philo Stone to a Shurelias.

Usually, you skill R > W > E > Q. You always get R on lvl 1, unless you are invading (E), and if you just want to clear as fast as possible you get W on lvl 2. If you want to invade and you think you are gonna cathc the enemy jungler, you should either skill your E (if he has no kill potential on you, like an Amumu) or your W (if its a good duelist like SHyvana/Lee Sin). If you only want to steal one of his buffs and get away, you can also skill Tiger on lvl 2, which will leave you without a deffensive skill on lvl 2, but 2 offensive skills, giving you the ability to clear a buff insanly fast, but throws you behind a little bit in general jungle/gank power and throws you behind a lot if you dont manage to steal that buff. If the enemy top laner is slow/has no escapes (Darius) and you are on blue side, you can gank him on lvl 2 with Blue buff, just to force a flash and return later with Red for a guaranteed kill.

You can do any route. You can start red for a lvl 2 gank (even tho I woudln't recommend that cause you run oom really reaslly fast) or you can start blue for the fastest clear out of any champ and for some amazing ganks after lvl 3 (MS masteries/runes make you outrun EVERYONE, red buff and stun are very strong ganking tools). Against weaker junglers (Amumu, Nautilus, even mundo early game) you can consider invading cuase you outduell/outrun every other champ int he game this early, beside a well played Olaf.

Your main point is early game really. late game, udyr is one of the strongest Tanks, but nothign more. Late game, the game is not in your hands anymore. You can slow down the enemy AD and be disruptive, but thats about it. If you want to carry a soloq game, do it early game. Against not very mobile mid champs (TF, Kassadin) try early (lvl 2,3 ) ganks, just to scare them away (if they push obv), do a lot top lane, it snowballs hard and top lane is easiest to gank for an Udyr (very tanky, can easily tank several towershots at lvl 3-4 already). If you figure the enemy team is pretty hard to gank (Ahri/Grag mid, Riven top etc), either just farm your jungle ( you can nearly keep up the 10cs/min with a well played phoenixdyr) or counterjungle. You can coutnerjungle every single jungler in the game since you are insanly fast in clearing camps and you run around really fast, but against some of them (Lee Sin, Olaf) you maybe shouldn't fight early, simply cause one mistake can cause them to snowball ahead and you do not want to do that. After clearing your jugnle, get some wards and ward the neemy jungle, steal his small camps and just set the enemy jungler back and yourself ahead. If you duoq iwth someone (or you have enough confidence) you can flash stun squishy targets (AP Mids) and if your laner isn't completly sleeping, you will probably be able to kill him, but thats easier to pull of if you are duoqing.

Dont buy Oracles to early, get at least 1 gp10 item before.

If you figure your taem has a shitload of dmg, you can also max Turtle after putting 2 points into phoenix (for better tower dives).

Mercs are a must on udyr, since cc makes him os much easier to kite. You can get Ninja Tabi early, but switch it for Mercs at least at ~25 min.