I don't have all that much to say about "Team Spirit", except that I'm glad Antonio's Clawzord transforms into a full-fledged standalone Claw Battlezord, rather than be another measly megazord attachment. I also found it cool that it had four modes, one for each direction on a compass - East, West, North, and South.
"The Tengen Gate" has one important question arise in the wake of the mass Mooger arrival: If the rangers have defeated every Nighlok so far, why is the Sanzu River now rising more than ever? Grant McFarland, who played both Sensei Watanabe and Lothor on Power Rangers Ninja Storm, returns as Daisuke, guardian of the Tengen Gate, and becomes just the latest Disney-era Power Rangers actor to guest on Samurai.
The battle at the Tengen Gate has several firsts (for Samurai, at least). Octoroo proves that he can hold his own in a fight, and Arachnitor, the Nighlok-of-the-Week, manages to defeat four of the rangers at once. Although the mutiny within the villains is nothing new, it's interesting in this case because Master Xandred simply took a break from commanding on his own, rather than be seemingly defeated by the new villain. Also, the usual punishment for a traitor in a series' group of villains is to either simply destroy them, or reprogram them into a mindless state. Here, Xandred gets creative and deals his newfound power upon Arachnitor in the form of torture (ouch).
Anyway, as an episode that ups the ante, similar to the MMPR "Doomsday" two-parter, "The Tengen Gate" certainly marks a change in routine for Samurai. Let's hope the stakes stay this high.